i understand the design decision behind the "limited combat zone" that centers around the current objectives, moves spawn points closer to them while disallowing anyone to get close enough to camp spawn points (well, not really but in theory)
the issue is that this inherently limits the freedom of movement, being able to flank and generally play smarter while promoting, or rather severely limiting everything else except being shoved into chokepoints and respawning somewhere close so you can repeat once you die. the already small maps are also even smaller since lots of potential flanks become "out of bounds".
the other big problem is that it creates a lot of really frustrating scenarios, from the infamous "what? you were defending a capture point? well you have 15 seconds to get from your cover and run away across a flat land with no cover from 20 enemies who just captured the point, otherwise you'll die as a deserter", to trying to shoot someone while your vision suddenly turns all red because you made a sidestep into restricted zone (example being trying to take back B as defenders in rakowice), or stuff like a russian tank parking on east street next to D on pavlovs, being protected by "spawn protection" against AT class who tries to get in range of AT grenade/satchel.
So, let us say we are at that point. How do we handle it. Do we let them spawn kill with impunity? Do we not allow them to kill players who have spawned, and instead allow them to die while their bullets do nothing?
remove the "dynamic" combat zones and make the spawn protection limited to only the furthest spawn point (= starting point of attackers, last objective spawn for defenders) and allow anyone to spawn there during the whole game, regardless the current objective state.
basically, it would work like a "safe point" while the current objective-dependent spawns would work more akin to the squad leader spawns. ie: you're trading being closer to the battlefied for the lack of spawn protection.
you avoid spawn killing by giving players more spawn points if it turns out that they are being camped. the spawn camper dies really quickly when people have an option to actually get out of spawn, so they'll just pick a different one and very quickly solve the issue themselves.
to make it more refined, decrease the "safe spawn point" spawn time (half, maybe even instant) so people don't need to wait 20 seconds in addition to spawning further from the action and on longer maps like bridges (although i don't think that map has even spawn protection issues), let people use spawn points that would only "unlock" later on in the game (so there's more choice than "being spawn killed in close spawn" and "losing few objectives because i wasn't able to spawn close enough")