Comment by Tor3

Zerotier works fine for me, but with a huge exception which I just can't figure out. On my Linux laptop which also runs OpenVPN and with some specific routing set up, Zerotier will, after a minute or so, completely take over the routing and default everything through Zerotier, and nothing I do with the routing tables will change this. I have to stop ZT at this point and then it reverts to normal. Every other computer in my ZT network behaves fine.

This is so problematic that I'm considering looking into Tailscale, I understand they work very differently but it looks like my use case could be covered by both.