Personally, that's why I didn't like the Stench campaign series at all. Trigger spawns everywhere. The chance is 50:50 that you're going to fail of a trigger spawn. Too much death traps.
There are so many custom campaigns out there, that are more than suitable for COOP or DIE, yet you chose a poorly-edited campaign in the entity way, Pat. I think you should add another campaign that's less buggy and more enjoyable.
That's why I didn't enjoy Rush for the Head, either.