Advice wanted for testing multiplayer and speeding up the iterations and packaging

Hi, so at the moment I package the game to a shared folder and run it on PC with one Steam account, and run standalone in the editor form my development PC with a different Steam account. This allows me to test multiplayer with advanced sessions, where one player invites a steam friend to play.

The problem is it takes forever to package. Is there a better way to test multiplayer with advanced sessions?