Using Base Lovelace Cards in Custom Config Template Card

Pardon my minimal understanding of code, but I think I’m missing something when it comes to creating a custom Lovelace dashboard via a custom template card. I’ve come a very long way with my dashboard, graduating from basic cards, to panel views, to 100% custom everything, but there are a few basic Lovelace cards I’d still like to employ but just can’t get them to work within the custom config template card or picture-elements card.

All my tabs are built the same: Elements, inside a picture-elements card, inside a custom-config-template-card, where as every TYPE of card is custom because only custom cards seem to work here. Is this by design or am I missing something?

For example, if I simply wanted to use the Lovelace Thermostat card, I get an error (relevant code included):

title: Home
views:
  - title: Misc
    panel: true
    cards:
      - type: custom:config-template-card
        entities:
          - light.zachs_lamp
        card:
          type: picture-elements
          image: /local/mobile_wallpaper.png
          elements:
            - type: thermostat
              entity: climate.hallway
              style:
                left: 50%
                top: 50%
                width: 15%

This results in “Unknown type encountered: thermostat”. But if I use any other “custom” card here it works just fine. And I’ve been fine with custom cards so far, but there’s a few Lovelace entities I’d love to use.

And just to show I’m not a total idiot, here’s my Spotify tab: