I would have to say no, because i hate it when im a medic and die, and someone swaps classes with me, then revives me, because then im stuck with their class, that i dont want to play with.
I
This is the reason. If I spend a ton of time thinking about what I like to have in a class, no matter which class, and somebody switches with me would just make me want to die, because I don't want to use their setup.
Another thing holding this back is, besides the ability to switch at command posts, since you would probably not be able to switch the entire class, you would pretty much just be swapping weapons, and a lot of games already allow you to pick weapons up off the ground.