Wireguard client communication without peer key via 1 router server
If you change the AllowedIPs setting of your client configs to AllowedIPs = 10.200.200.0/24, all the clients' traffic to the 10.200.200.0/24 block will be routed through their WireGuard connection to the server. This will allow you to connect from one client to another using their WireGuard addresses -- eg ping 10.200.200.4 to ping client2 from client1.