Blacklist everything then whitelist the IPs you know you’ll be connecting from (work, cell phone, etc). I don’t connect from random places usually. If I need to then I use cellular. You might be better off with a VPN if you need to connect from random places.
I see, thanks!
Is there any concern with whitelisting a cellular CGNAT’s public IP? Presumably that would potentially whitelist thousands or tens of thousands of other mobile devices at once, wouldn’t it?
Unless it can natively run all the existing ready-to-go Pi images and software packages and will also receive community support when I ask for help in a Pi-adjacent forum it’s not really going to be a competitor to the Pi. The hardware is pretty much irrelevant.