I have something you may really like and I’ll get it submitted as a community contribution in to the helper library repo this week. I’ve been testing and tweaking it for over a year now and I’m way past due in getting it to the community. I last mentioned it here with some more detail. It’s very simple, very similar to what you are doing, and very quick. And it uses the same concept, where adding/changing/removing a device to the automation is as simple as adding it to a group. If it’s lighting depends on lux, then add lux triggers and values to metadata. If the action needs a timer, add it to metadata.
Basically, take all of the logic out of your rule and put it into groups, with Area_Triggers and Area_Actions as groups using the associated Items DP. Very similar to what you’ve done! I think we’ve actually communicated about this before.