
One issue that comes to mind, is that while this system makes it very easy for an underpopulated faction to prevent a zone from being locked, it is still virtually impossible for them to lock the zone themselves.
I like that BOs generate points over time, and that AOO increases the rate at which these points are generated for the underdog realm. Currently the only purpose they serve is requiring X points to be able to attack a keep; what if having Y points would lock the realm for you completely? With this change, the keeps themselves might just generate more points at a faster rate than BOs.
The zerging realm would be at a disadvantage already with their BOs being worth "less," so they would be incentivized to attack keeps to secure the additional point generation. It's easier for the underdog to defend a keep than it is to attack it, especially with a reliance on the ram to damage the door.