You shoukd investigate the Node Red docker “flows”. It allows more complex scenes and you can share them with people if they mess them up.You could just use a switch node with two outputs to do that.
Also there is a paid version of Tailscale and if you pay you can join multiple tailnets. Set up a free tailnet for each installation and then you’ll have access through your own tailscale account through Tailscale’s secure Wireguard VPN tunnels .You would still need a password but it’d be a lot easier than setting up port forwarding securely.