I have a trick for those who map in CSGO or other Source engine games

I found a little timesaver trick for when you are compiling maps in the hammer editor. Allow the game to run after compiling (untick the box) and then in the Additional game parameters: box you can add -hijack and it will open the map in the same CSGO game instance you were using instead of telling you that you can't open multiple instances of CSGO

This allows you to quickly recompile your map and not wait to launch CSGO again. This also works well in GMod so you don't have to reload all your addons again