Hmm... so basically pushing into a system with a directed colonization rather than an undirectable BGS push... that might be nice.
I see a problem though, almost all systems around us are already at max factions. So we wouldn't be able to get our faction in there without kicking an existing one out. That can be a major pain. So many things can block it happening and if the faction even pokes its head over the boundary, they escape the eviction. Hope FD look at that mechanic at some point.
What I agree with is that any PCM would have very strict criteria as well have a high cost. That being said one of the rewards for colonizing would be add Net Worth to the minor faction allowing that minor faction to grow and become more active in the Galaxy. That is why I feel it is important to have a blocking mechanism in place to give commanders a fighting and fare chance to stop any and all unfriendly and unwanted colonization attempt.
I would also like to add that any PCM would have to be into a unpopulated system.