Getting additional data from device during mqtt discovery (e.g. device alias)

What I am aiming to do is to send along with the /config discovery payload additional data such as a device name that can be used in lovelace.

I have a fully functional custom relay bank device (nodejs code) sending the mqtt config discovery payloads for each relay to HA. That’s all working fine.

In my backend/device I have a yaml file that configures the hardware and sets an id and name/alias for each relay.

  - id: zone_1
    relay: 1
    alias: Front Yard North
    gpio: 80
  - id: zone_2
    relay: 2
    alias: Front Yard South
    gpio: 73
  - id: zone_3
    relay: 3
    alias: Front Yard Beds
    gpio: 69

so my nodejs backend code publishes payloads like so to the /config topic

------ sending discovery payload to HA for  Front Yard North : zone_1 -----
topic=> homeassistant/switch/irrigation/zone_1/config

In the front end (lovelace) i use this jinja2/yaml to generate the cards

# lovelace_gen
{% set zones = {
'1':'Front Yard North',
'2':'Front Yard South',
'3':'Front Yard Beds',
'4':'Back Yard East Spigot',
'5':'Back Yard Garage Spigot',
'6':'Back Yard West Spigot',
'7':'Garden East',
'8':'Garden West'
icon: mdi:water
  - type: vertical-stack
    - type: markdown
      content: >
        # Irrigation
    {# - type: horizontal-stack
      cards: #}
    {% for zone,name in zones.items() %}
    - type: entity-button
      entity: switch.irrigation_zone_{{ zone }}
      icon: mdi:water
      name: {{ name }}
        action: toggle
    {% endfor %}

as you see I have “hard coded” in the lovelace yaml the alias names of my entities and used those in the entity name prop. That is not ideal. I would like to get those aliases from the backend yaml to use in lovelace

I thought I could attach extra data in the device key of the mqtt switch in the config payload but whenever I do that HA fails to discover the entity

{"name":"irrigation_zone_5","device":{"manufactuerer":"uci","name":"Back Yard Garage Spigot"},"command_topic":"homeassistant/switch/irrigation/zone_5/set","state_topic":"homeassistant/switch/irrigation/zone_5/state"}
let payload = {
  name:`${opts.namespace || NAMESPACE ? `${opts.namespace || NAMESPACE }_` :''}${}`,
   device: {  // here I try to add the device key to the json but it causes entity not to be discovered
     manufacturer : 'uci',
     name: ent.alias,
  command_topic:`${topic}/${opts.command || COMMAND_TOPIC}`,
  state_topic: `${topic}/${opts.state || STATE_TOPIC}`

So how can I get additional data from my device (either in the config payload or via another topic - mqtt sensor?) to the HA frontend (lovelave) for use in the jinja template? (or HA template)?

the lovelace gen component can’t access (backend) states so even if I can get the extra entity info to HA via mqtt I won’t be able to access it via the lovelace yaml.

So the answer is 'no can do thisa way"