I made a small utility for two PC stream setups called FindWindowLAN. When run in "Send" mode, it will broadcast the foreground window title to a PC on the same network that's in "Receive" mode. This lets applications like OBS Studio's automatic scene switcher function on your encoding PC, as it thinks the application is open locally. The name comes from the Windows API call "FindWindow", which many applications use to find an active window.
Download: FindWindowLAN.zip (8KB)
How To Use
Run one copy on your gaming PC in "Send" mode. Put the other one on your streaming PC in "Receive" mode and make sure it's the active window. The two PCs must be on the same local network, and any firewall / security software must allow broadcast traffic to pass.