I've hosted tons of lobbies where I modded the spawns so there's 40+ Minigun/Medic Dozers and Cloakers on the map at once, but I rarely ever hosted this heist after I got the achievements because the nature of the spawns meant I always ended up camping the exact same spots every time (or just cheesing it by killing everything with Graze, Poison Grenades, etc).

So I went to edit the map to change the spawns so that they mainly spawn from the central area and not from places where they can shoot the player in every direction and also edited a few other things (like more variety in viable spots to go to).