I used to (when I did that more) set up a bond of my wireless and ethernet devices, so when ethernet was plugged in it was preferred, otherwise it would use wireless. It was pretty seamless, and provided the same MAC on both networks.

I used to do that too. Nowadays I just run a WireGuard VPN and treat my WiFi network as "untrusted" (which is a good idea anyway) and it's more seamless if IP addresses change, or even if I leave the house and go somewhere else - I can expect most connections to stay up.