Bog basic question:

Is it possible to increase defensive structure DPS somehow?

In the early game, stuff like Drone Bays can be terrific for maintaining control of an area.

As the game progresses, though, units tend to get more chewy, and the basic buildings then become a little less useful.

By late game, the buildings melt fairly easily. 

I know that you can increase the toughness/resistance of the structures, but that doesn't necessarily have an impact on their DPS.

Aside from building more of them, is there any way to make the buildings deal more damage?

It would be great if there was a way to make defensive structures keep pace with the increasingly tough and powerful units (as an upgrade option, among the others).