I have window AC units in my kids bedrooms. They stay off during the day, but turn on several hours before bedtime depending on the outside temperature. It isn't a terribly smart automation, just a "turn on at 4pm if temp over 100F, 5pm for 90F and 6pm for 80F."
Originally I was trying to do it based on delta t between the room and the outside and the target temperature and the estimated cooling efficiency, then I had to start figuring in how humidity and feels like temperature would affect things. And so after over thinking and over engineering it, I ended up at the stupid solution of just switching on at fixed times based on outside temperature being over a threshold and it works pretty well.
Smart plugs, I have two on sonoff s31 reflashed with esphome and one on a third reality zigbee plug. These are all smaller units, about 8000 BTU.
But... I had to put the big one downstairs on a smart plug for completely different reason. It is a ge smart ac with wifi, but once in a while it gets into a state where when it tries to start up but consistently trips the breaker. So the smart plug simply cuts power for 5 minutes when it notices the ac is pulling more amps than what it is supposed to.
But yeah, I inspect regularly and try to avoid running these things when nobody is around. I had a 30amp smart switch on and outdoor outlet which would trip whenever I plugged in a weedwhacker and it ended up looking scorched, clearly rated for 30amp but not capable of doing even half that because the 16 amp breaker never tripped.