Sounds like a neat setup - can you self host the smart plug control (Home Assistant?), or do they connect to third party servers?

It's a Shelly S. Among the many ways to control it I'm using its local web server to turn on and off the power from my phone, and a curl to do it from my scripts. I'm also polling the url for reading the power level and know when a shutdown is complete, before turning off the power. I think it can be interfaced by home assistant and similar platforms but I never tinkered with them. Self made small scripts are more than enough for my use cases.