I'm not arguing against any of the points made here, I think they are valid techniques, but I think the entire HAB/FOB mechanic is getting increasingly gamey. Obviously, I don't know what the final plans for the FOB teamwide spawn mechanic are and this could simply be an interim solution. If you look at what a FOB is supposed to correlate to IRL, a small base, and how an enemy would take that down, by either forcing a retreat, cutting off reinforcements and killing everyone inside, or over running it, I don't see why a single symbolic radio, that can be hidden in a bush and that ONE soldier can remove is the key to taking it down. It just seems silly, as well as the game mechanics that have developed in response to it.
I like the increased size of the HAB and what that has done, that should be kept. Having X number of enemy within the spawn point radius increasing the spawn times is also good. If you want to simulate a base being overrun by the enemy, these things do that, once the enemy has numerical superiority within the spawn zone, it already stops spawning, just give it a set amount of time in that state and *poof* the spawnpoint vanishes. No more searching for a hidden radio, or shoveling down a bunch of wire and sandbags around it. No more, "Someone is on the radio! Everyone leave the base and run over to where we hid it to kill the two guys trying to dig it up!!" All that stuff has no bearing in reality. It should be simple, gain control of the FOB itself and you kill the spawnpoint. To defend the FOB, stay and defend it.
As far as spawnkilling goes, big deal. It still happens now, it will always happen as long as spawnpoints exist, splitting the spawn and radio only change how it happens.