For king of the hill, leaving the point is kind of silly anyway. Sure its not required to be in there, but you still need to defend it for the sake of winning. I don't see a need for a change there.
For crazy king, these matches can already take a long time, and losing teams still have a chance to come back from a deficit. Crazy king matches have a lot of dynamic strategy involved, and both teams need to work out on the fly how to gather the max points. With the cap bubbles being so small, you'd effectively be putting the holding team into 2v3 scenarios, followed by cleaning up the remaining ship locked to the cap bubble. I just see it increasing the time of the matches for no real gain.
Same thing with same amount of ships on the point.