Anti-Personal Drone module is too weak, and sInce APD module is effectivly 10% more manpower even in comes boarding, but APD modules don't prodect manpower from crew kill damage, all manpower modules do a better job at protecting you from loosing your ships to boarding and provide more versitlity to your ships.

now how do I think to buff the APD module? 

50 bonus "manpower" in every ship battle 

with this makes it that you allways have atleast those bonus manpower in battles protecting your ships from boarding. 

Note that the bonus manpower doesn't take manpower resource, nor does they count towards the crew boni, they are the drones.

The best drone defense unfortunatly is offense. Flak. The defense modules in this game from flottilla shields to stacking repair modules and fleet accelerators and the not knowing how a large slot vs a small slot effects the defense modules are in the greatest need of a rework or a balance pass. This also includes the weapons that disable shields and weapons and there corresponding defensive tools. It still amazes me how weak in general the defensive tools are to the offensive ones in this game. 

Considering we don't have that many utility module slots, I too feel there should not be anti-boarding only module in the game. First it's not that effective at it's job, second it's stupidly expensive and last completely useless if no boarding occur. It does need a buff to be worth using.

boarding pod can reach ship quit easy already, just have some swarm missiles as well