Definitely will work for a scheduled reboot (many routers already have that feature in their admin function). I may have misunderstood but I think the original requirement was for a reboot request on...

Solid red would make me think no wifi connection rather than failed to get IP. Reserving an IP can sometimes help apps find them but of course doesn't help if they can't connect to wifi. I have...

Are you certain that it's the device dropping from the network (I think it stays solid red) vs the app not being able to find them? That would change your troubleshooting steps. Mine are rock solid...

You could use IFTTT or perhaps an aftermarket app to bypass kasa. But it sounds a bit dangerous, esp with IFTTT as it's not 100% reliable and sometimes slow - so you need a contingency for the case...

If your internet is a bit flaky you may not have access from a cloud service to fix it... Alexa, Google, IFTTT, et al, and TP Link remote access all need to connect from the internet to do something...

Sure - if you decide to give it a try you'll need an old android phone (or a low end pay-go android phone from bestbuy/walmart/target, etc, no need to activate it) that you'll leave at home running...