@gsuberland Yes. Which is why I said "careful attention to failure modes".
For example, relay outputs for wall receptacles would be normally closed, and there would be a watchdog (or manual killswitch) that would shut down the controller on failure and make them passively turn on.
Key lighting circuits would be 2-gang boxes with the second switch (normally left on) controlling power passively.
@azonenberg that's my point though, with that setup the failure mode is "all your lights are stuck on". that's not an acceptable failure mode in my eyes. the only failure mode I want is that the house functions *precisely* the way it did before I installed anything smart.
imo the way to do that is by having every switch point internally contain an SPDT physical switch wired to an SPDT relay in the same way as you would with a lighting circuit with two switches.
@gsuberland @azonenberg
The Shelly Pro's might get close; they have ethernet (and wifi and bluetooth) - but they also have a pair of locally programmable interfaces. So I think you could wire a physical light switch onto the 'SW1' and script it to use that to operate locally;
https://www.shelly.com/products/shelly-pro-1?_pos=10&_fid=34a228ceb&_ss=c
