I'll usually avoid spawning a heavy vehicle if the boss or a couple of them are low on health and I have competent teammates if I'm already in the respawn screen. In that scenario, it can be better to just spawn a heavy weapon, Ghost or Banshee so you can get there before the boss gets killed while also being able to inflict some damage to get credit.
Yeah but see the thing is, we're talking about situations where the bosses aren't necessarily on low health. Haven't you ever been on Apex 7 at the end of round 4 when you're on that one side of the map, and then round 5 is the Grunt Goblin round on the other side of the map, and you want to fight it with a tank but it would take half the round just to lumber on over there with your Scorpion? That's the kind of thing we're talking about here.
If the bosses are low on health and your team can finish them off, then yes obviously you want to get there quickly with a Banshee or something, but the point is that there are some rounds where the best choice of vehicle depends more on how fast it can get you to the objective from where you are, rather than the effectiveness of the vehicle against the boss itself, which is silly. Allowing us to pick which base to spawn our vehicles out of in Warzone Firefight, no matter which req station we're at, would be a huge improvement and immensely beneficial.