Let players spawn in gunner seat of vehicles in base

Currently if a teammate takes the Attack Heli in base, you immediately lose the ability to spawn on that vehicle unless you're in their squad. I understand this being the case once they're out and about, but when they're still in base this sucks. If I am waiting for the heli, someone else takes it, and they're not in my squad, I can't spawn on that heli even if it's still in base and has an open seat. I've seen dozens of helis leave base with no gunner like this. Playing vehicles without a gunner sucks in this game, and not being able to gun for a vehicle that has that spot open also sucks.

Please ensure all vehicles (MBTs, helis, etc.) can fill their seats while they are still in base.