Client and Server on different Subsystems

I wanted to ask if it is possible to have the Server (Dedicated) running on the IP Subsystem and a Client joining over IP but while connected to Steam. In order for other Steam user to be able to see, that the Player is in a game and maybe join over steam to that dedicated server. Basically Steam should be a secondary Subsystem and IP the primary.

I found this forum post about different Subsystems and that it is blocked by Epic because if overridden causes crashes. Forum Post. I tried to override that check and it crashed the server. Server Crash

But I also read about using multiple Subsystems at once but can’t find any guide.

So either is it possible to fix that crash or to have a secondary Subsystem like Steam running, that does not handle Server Client communication, but allows other Players to join.

Thanks in advance.