Honestly… I kinda think three microcontrollers is way overcomplicating things preemptively. I would try just a single MCU first, and see if the response time is adequate. If there’s any sort of noticeable input lag or delay, then try the multiple MCU route.
As someone who grew up in a house that was definitely too small for a 4-person family, it makes keeping the house decluttered a lot more difficult because there’s just not space to put things away. And god forbid you aquire NEW things, because then you have to shuffle everything around to make a place for it or it just ends up laying around.
You just need to be careful that the supplies’ outputs are completely isolated from mains. Otherwise you’ll end up with a lovely spark show.