I’m not super familiar with port forwarding on WSL, but I assume it does some sort of NAT, right? In that case, I suspect it would be enough if only the listening socket(s) on each server had a fixed port which is correctly forwarded? (as then all other sockets that are accepted will have a random port but the NAT would be aware of them and would handle them)
Unfortunately, at this moment, also the port of the listening socket(s) is picked at random (well, not at random, but we’re letting the kernel give us back an arbitrary available port). We don’t support a way for the user to specify a port. Which I think means there’s no real way for you to set up port forwarding before launching the application.