You can manually disable key expiration for hosts in Tailscale, and I think you can do it with tags too...
https://tailscale.com/kb/1028/key-expiry#disabling-key-expir...
The word "auth keys" meant nothing to you, I guess: https://tailscale.com/kb/1085/auth-keys
The word "auth keys" meant nothing to you, I guess: https://tailscale.com/kb/1085/auth-keys