You might be able to hurry the CPs along by building fighting positions and/or caches, as making them gives command XP.
one Pathfinder crewed AT gun
Kinda OT: You know they keep their upkeep and reinforce costs when they are on an AT gun, right? I get why you are doing it, but it seems like you would be better off using a different squad to provide vision for your AT gun than to have an ATG that can spot for itself but takes up 8 pop.