I will be short on explanation.
Airborne troops.
No....
AIRBORNE TROOPS!!!
I imagine that like dropship attachement that allows PO to drop marines to the ground due flyby missions.
This can extend strategic potential of marines and give them more mobility. Since the main marine tactics is a turtle defense (i think 70% of all times), i imagine that is a good tweak to add some action to gameplay. Potentially it will allow to break through this boring bottleneck sieges.
The main question is how you will designate drop zone.
The first idea it's a red dot mode on bino. The worst thing about it, that's seriously limits the field of application.
Second idea, drop zones will be static and will be scattered around the map from the beginning. For example this can allow you to drop scout group before main drop or drop squad for potential flank.
Discuss?