Wireguard server an client simultanly

Installing and Using OpenWrt
1

Is a setup possible with wireguard works a client for vpn provider connection and simultanly works as a server for road warriors?

2

Sure you need Policy Based Routing:

If your WireGuard client does not have a listen port (and it should not have one) the PBR 1.1.7 package will take care of it automatically

3

Thanks for the hint.