Everything I use is in Docker too, I’d much rather use Docker than mess around with host files, but to try it out I don’t mind. If you have an image you could share, I’d appreciate it.
Anyway, neither are clients or servers as I just used ZeroTier as a quick setup. On my other infra I use wireguard with the VPS being the server (that setup works well but I only reverse proxy HTTP stuff so X-Forwarded-For works well).