Yaml expart advice wanted (custom:stack-in-card related)

I am reasonably new to HASS and Yaml. Although AI is a good help, I am now struggling with something, which I expected to be simple, but cannot get it working. I have a panel definition containing a custom stack in card with 2 rows of buttons. The first I tried, is to get this card with buttons bottom aligned (so it is always at the bottom of the page).
The second I like is somehow (include! ? ) make this modular, so I can have those buttons a the bottom of several panels (without copying its definition)

Anyone whos is experienecd and know how to accomplish this ?

##############################################################
# WALL PANEL DASHBOARD - Starting Point
# Required custom cards (install via HACS):
#   - layout-card
#   - mushroom-cards
#   - stack-in-card
#   - card-mod
#   - mini-graph-card
##############################################################
- title: Home
  path: panel-1
  type: custom:grid-layout
  layout:
    grid-template-columns: 1fr 1fr
    grid-template-rows: auto auto auto auto auto auto auto 1fr auto
    min-height: 1920px
    grid-gap: 8px
    padding: 8px

  anchors:
    _light_card_style: &light_card_style
      card_mod:
        style: |
          ha-card {
                --card-primary-font-size: 24px;
              }

    _light_switch_style: &light_switch_style
      card_mod:
        style: |
          ha-card {
                aspect-ratio: 1 / 1;
                padding-bottom: 8px;
                --card-primary-font-size: 24px;
              }

    _nav_button_style: &nav_button_style
      card_mod:
        style: |
          ha-card {
                --ha-tile-info-primary-font-size: 24px;
              }
              ha-tile-icon {
                --mdc-icon-size: 60px;
                --tile-icon-size: 80px;
                --tile-icon-border-radius: 50%;
              }

  cards:
    ##########################################################
    # BADGES ROW
    ##########################################################
    - type: custom:mushroom-chips-card
      view_layout:
        grid-column: 1 / -1
        grid-row: 1
      card_mod:
        style: |
          ha-card {
              display: flex;
              flex-direction: row;
              flex-wrap: nowrap;
              align-items: center;
              justify-content: stretch;
              --chip-icon-size: 48px;
              --chip-height: 58px;
              --chip-font-size: 26px;
          }
          ha-card > div {
              display: flex;
              flex-direction: row;
              flex-wrap: nowrap;
              width: 100%;
            }
            ha-card > div > * {
              flex: 1 1 0;
              min-width: 0;
              max-width: 20%;
              overflow: hidden;
              justify-content: center;
            }
      chips:
        - type: template
          icon: mdi:alert
          content: "{{ states('sensor.washing_ready') }}"
          icon_color: red
        - type: template
          icon: mdi:battery
          content: "{{ states('sensor.battery_status') }}"
          icon_color: >
            {% if states('sensor.battery_status') | int > 20 %}green{% else %}red{% endif %}
        - type: template
          icon: mdi:trash-can-outline
          content: "{{ states('sensor.afval_buiten') }}"
          icon_color: orange
        - type: template
          icon: mdi:washing-machine
          content: "{{ states('sensor.washing_ready') }}"
          icon_color: blue
        - type: template
          icon: mdi:home-account
          content: >
            {% if is_state('binary_sensor.presence_home', 'on') %}Thuis{% else %}Weg{% endif %}
          icon_color: >
            {% if is_state('binary_sensor.presence_home', 'on') %}green{% else %}grey{% endif %}
        - type: weather
          entity: weather.home
          show_conditions: true
          show_temperature: true
        - type: template
          icon: mdi:clock-outline
          content: "{{ now().strftime('%H:%M') }}"

    ##########################################################
    # ENERGIE OVERZICHT — left column
    ##########################################################
    - type: custom:mini-graph-card
      view_layout:
        grid-column: 1
        grid-row: 2
      name: Energie overzicht
      icon: mdi:lightning-bolt
      entities:
        - entity: sensor.energy_consumption
          name: Verbruik
        - entity: sensor.energy_solar
          name: Zonnepanelen
          color: "#f9a825"
      hours_to_show: 24
      points_per_hour: 2
      line_width: 2
      font_size: 75
      animate: true

    ##########################################################
    # CAMERA VOORDEUR — right column
    ##########################################################
    - type: picture-glance
      view_layout:
        grid-column: 2
        grid-row: 2
      title: Camera voordeur
      camera_image: camera.voordeur
      entities:
        - entity: binary_sensor.voordeur_motion
          icon: mdi:motion-sensor
        - entity: lock.voordeur
          icon: mdi:lock

    ##########################################################
    # SLIDERS VERLICHTING WOONKAMER
    ##########################################################
    - type: custom:stack-in-card
      view_layout:
        grid-column: 1 / -1
        grid-row: 3
      title: Verlichting begane grond
      mode: vertical
      cards:
        - type: horizontal-stack
          cards:
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: Eettafel
              show_brightness_control: true
              show_color_temp_control: true
              collapsible_controls: false
              <<: *light_card_style
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer_ct
              name: Salontafel
              show_brightness_control: true
              show_color_temp_control: true
              show_color_control: true
              collapsible_controls: false
              <<: *light_card_style

        - type: horizontal-stack
          cards:
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: Plint keuken
              show_brightness_control: true
              show_color_temp_control: false
              collapsible_controls: false
              <<: *light_card_style
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: TV wand
              show_brightness_control: true
              show_color_temp_control: false
              collapsible_controls: false
              <<: *light_card_style
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: Schemerlamp bank
              show_brightness_control: true
              show_color_temp_control: false
              collapsible_controls: false
              <<: *light_card_style

        - type: horizontal-stack
          cards:
            - type: custom:mushroom-light-card
              entity: light.dev_light_switch
              name: Hulsta kast
              layout: vertical
              secondary_info: none
              <<: *light_switch_style
            - type: custom:mushroom-light-card
              entity: light.dev_light_switch
              name: Schelp
              layout: vertical
              secondary_info: none
              <<: *light_switch_style
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: Gang plafond
              layout: vertical
              secondary_info: none
              <<: *light_switch_style
            - type: custom:mushroom-light-card
              entity: light.dev_dimmer
              name: Gang koofjes
              layout: vertical
              secondary_info: none
              <<: *light_switch_style
            - type: custom:mushroom-light-card
              entity: light.dev_light_switch
              name: Spot Amadeus
              layout: vertical
              secondary_info: none
              <<: *light_switch_style
            - type: custom:mushroom-light-card
              entity: light.dev_light_switch
              name: Spot TV
              layout: vertical
              secondary_info: none
              <<: *light_switch_style

    ##########################################################
    # SPACER — pushes bottom block down
    ##########################################################
    - type: markdown
      content: " "
      view_layout:
        grid-column: 1 / -1
        grid-row: 8
      card_mod:
        style: |
          ha-card {
            height: 100%;
            min-height: 300px;
            background: none;
            box-shadow: none;
            border: none;
          }

    ##########################################################
    # SCENE BUTTONS + NAVIGATION — bottom
    ##########################################################
    - type: custom:stack-in-card
      view_layout:
        grid-column: 1 / -1
        grid-row: 9
      mode: vertical
      cards:
        - type: horizontal-stack
          cards:
            - type: custom:mushroom-template-card
              primary: Slapen
              icon: mdi:sleep
              icon_color: indigo
              layout: vertical
              tap_action:
                action: call-service
                service: scene.turn_on
                target:
                  entity_id: scene.slapen
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: TV kijken
              icon: mdi:television-play
              icon_color: blue
              layout: vertical
              tap_action:
                action: call-service
                service: scene.turn_on
                target:
                  entity_id: scene.tv_kijken
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Muziek
              icon: mdi:music
              icon_color: purple
              layout: vertical
              tap_action:
                action: call-service
                service: scene.turn_on
                target:
                  entity_id: scene.muziek_luisteren
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Eten
              icon: mdi:food-fork-drink
              icon_color: orange
              layout: vertical
              tap_action:
                action: call-service
                service: scene.turn_on
                target:
                  entity_id: scene.eten
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: TBD
              icon: mdi:help-circle-outline
              icon_color: grey
              layout: vertical
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Instellingen
              icon: mdi:cog-outline
              icon_color: grey
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /config/dashboard
              <<: *nav_button_style

        - type: horizontal-stack
          cards:
            - type: custom:mushroom-template-card
              primary: Home
              icon: mdi:home
              icon_color: blue
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/home
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Tuin
              icon: mdi:flower
              icon_color: green
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/tuin
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Camera
              icon: mdi:cctv
              icon_color: red
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/camera
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Energie
              icon: mdi:lightning-bolt
              icon_color: yellow
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/energie
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Status
              icon: mdi:information-outline
              icon_color: cyan
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/status
              <<: *nav_button_style
            - type: custom:mushroom-template-card
              primary: Admin
              icon: mdi:shield-account
              icon_color: deep-orange
              layout: vertical
              tap_action:
                action: navigate
                navigation_path: /lovelace/admin
              <<: *nav_button_style