I've proposed two separate ideas on one picture.

Idea 1: We simply expand the current airlocks to 2x1 instead of 1x1. This would remove the ability for xenos to bottleneck/disarm spam any marine attempting to shoot them, and other stuff
Idea 2: this would be a bit more tricky, but would completely remove airlocks all together. Obviously this would be more suited for a land map.
Yeah? Yeaaaahhhh