Decluttering card breaks card_mod on fold-entity-row

consider these secrets:

style_label_margin:
  style: |
    .label {
      margin-left: 0px !important;
    }
#      color: blue !important;

style_toggle_icon:
  style:
    ha-icon:
      $: |
        ha-svg-icon {
          color: var(--primary-color);
          width: 24px;
        }


and this decluttering template:

card:
  type: custom:fold-entity-row
  card_mod: !secret style_toggle_icon
#     style:
#       ha-icon:
#         $: |
#           ha-svg-icon {
#             color: var(--primary-color);
#             width: 24px;
#           }
  head:
    type: section
    label: '[[name]]'
    card_mod: &label
      !secret style_label_margin
  padding: 0
  entities:
    - entity: switch.[[id]]
      secondary_info: last-changed
      state_color: true
    - entity: sensor.[[id]]_actueel
    - entity: sensor.[[id]]_totaal

    - type: custom:fold-entity-row
      card_mod: !secret style_toggle_icon
      head:
        type: section
        label: Details
        card_mod: *label
      padding: 0
      entities:
        - 

does not transfer the top card_mod for style_toggle_icon. Ive tried many things, also use the verbose card_mod, but it simply does not work. the second one, on the style_label_margin is fine.

even more surprisingly, the nested identical mod ( Details) does work as supposed:

anyone else seeing this too?
probably need to file this in decluttering, because the identical mod is used in over 350 other places and working correctly. I just dont get why this would be the case. So hope anyone else seeing this can comment.

This is wrong CSS. The color is for which class, id, tag, …?

thats a c&p error from my commented notes… Ill edit it above
I use the colors to see if the mod works, and to make it stand out from other mods during testing

btw, had this surprising experience yesterday: I move all (over 350 Fer cards) mods from the cards yaml config to the secrets file, and imported them like above. I noticed the processor % go from a generic 10-15 to 30%! I couldnt believe what was happening, and restarted a few times, to be sure there was not some other activity going on causing that. Not the case.

It took me the rest of the afternoon to edit them all back in the yaml cards directly, and only use &anchors inside the smile yaml files, and saw the % drop back to the usual figures.

I didnt expect that at all.

btw if you have a moment, could you have a look at (How) can we move the label to the left · Issue #203 · thomasloven/lovelace-fold-entity-row · GitHub ? I am trying to make a more fundamental change but cant find the correct edit…