Trigger when group-members are "unavailable"?

Just took a power-hit and caused all my esphome smart-plugs to reboot.

I’m now trying to write in a rule to turn on my s31 plugs if they go from state “unavailable”->“off” when conditions say they should be on.

This works fine for things that are one-off plugs (not in a group), but some I control in groups (e.g. group.all_radios; group.livingroom_lamps). It seems the group (even when all the plugs are “unavailable”) remains “off” or “on” and never “unavailable” (even if all members of the group show “unavailable” individually).

Is there some way I can have a trigger for unavailable->off without specifying each individual plug in the group within the automation trigger again? I’d like to keep it as encapsulated as possible so I can make changes in 1 place when I add or remove something.

I’m willing to accept it only being “unavailable” if all members of the group go out at once (the most likely case if power goes out), I don’t need it to be separate out of sync.

Just realized I forgot to set the category and tags, hopefully now the right person can find and help me…