Yeah, and this is totally why blizzard did it too.If the DEVELOPER OF THAT GAME wanted to add a mission it should be able to be loaded from a menu in that game as part of that game. Not exit, go to lobby run mutator. Not exit, run startscript go to mutator, hope gamedev didn't forget to maintain mutator.
Ninja hint: you can already lua it!should be able to be loaded from a menu in that game as part of that game