I think it's a decent idea that will:
a. Prevent a vulch fest
b. Enable someone to actually disengage and fly home (cause believe it or not, some of us like to actually land our kills).
c. Promote territorial SA in addition to "in-plane" SA. "The blinking base complacency theory"
However, it will:
a. Allow bases to be taken easier on any given attempt.
b. Piss off whomever decides to up from the capped field.
c. Create HUGE whines on 200 and here.
We in The Flying Circus have a few cardinal rules (that get broken regularly by some of us) and one of those is: Never fight over an enemy base.... We call it Vati's rule #1.
Overall, since HTC decided to put the strategic targets as a back seat to the tactics and tactical, (I played back in the early days when things worked somewhat differently) this would allow more fluid battlefield, more resets, map changes and perk points gained. I would temper the penalty though by making it set you back one base instead of two. This game, while decent, has gotten that infinite life, first person shooter/Call of Duty mentality for a good part of the community. Nobody likes the bomb-and-bailers and I think it would be worth trying it at least on an experimental level.