I’d like to say I got the setup right the third time, but I didn’t, though I think it helped me understand better why groups are so deeply buried in Home’s UI. I had forgotten that after a group is set up, its component accessories are no longer available in Home’s UI. This makes sense if you have a lamp with two bulbs in it that you always want to come on at the same time and behave in the same way, but it’s a limitation that greatly reduces the utility of groups because it means the individual accessories that make up a group cannot be added separately to scenes. I backed out of the partially built scene realizing that I had to reconfigure my group.
The solution was to ungroup my desk lamp from the rest of my lights in the studio and set up a scene that turns the desk lamp red and a workflow that triggers that scene when the back door opens. The trouble is, scenes have a very limited concept of state so my lamp can’t be toggled back to its prior color using an automation workflow or by toggling the scene manually. I could add a timer to the automation to turn the desk lamp off after a certain amount of time, but I don’t want to turn off the light, I want to turn off the scene, and you cannot attach timers to scenes. Instead, I needed another scene to return the desk lamp to its original settings.
You probably get the point by now. Home is both too complex because of the way it splits things into rooms, zones, groups, scenes, and automations and too simple because it lacks features like robust state awareness and, in some places, timers. However, the problems with the Home app run even deeper. They are compounded by a generic UI and complex navigation.