Cheers, that's pretty cool! I've looked into scrcpy before, but never got around to testing it. The way you present it is super easy, so I will definitely give this a shot!
Regarding my problem, it seems it wasn't as fixed as I thought :p The connection issue described in the original post still comes once in a while, not sure what triggers it, but it usually resolves if I ping the device and run iptraf to monitor the traffic. Probably superstitious, seems weird to me that it should fix it. It also happened once between my laptop and my new machine, so it was not isolated to the phone after all.