I would hate to have to alt-tab out of a currently-unstable (or any) game in the case that I had forgotten some tiny detail. It needs to be in-game, and changes should be possible during the actual round.
Thinking of CoD, it really sucked to have to DC from a server, just for something as simple as switching your grenade from frag to molotov. That said, there needs to be a way to stop your entire team being little geeks and hiding in the lab the entire game. Think of BF2 now- of the huddles of idiots camping the hangars and gunship helipads. Sometimes half your entire team would be sitting there with their thumbs up their asses instead of being on the battlefield! (Quite ironic. They are playing a game called "Battlefield" and the majority of the time they are assing about in a hangar instead of on the namesake of the game.) This is what may happen with the introduction of the in-fight mechlab.
(Battlefield -> Camphangar / MechWarrior -> MechOutfitter)
I could suggest that players need to be in spectate mode to be able to make changes, but I think that would just make the problem worse, and create a new one-
constant autobalancing. Therefore having to be spectating is
NOT the solution. There would be no way of predicting how many players from each team are going to be changing out to spectator or for how long. Teams would spontaneously become hugely unbalanced and the auto-balancer would get to work.
Anyone here played TF2? Any of you been suddenly switched to the other team, just as your team got the upper hand? I have. It pisses me off VERY much. The kind of frustration you get from spending an hour on something, only to have it crash just as you were about to click save. With teams constantly switching in and out of spectator, team numbers and balance will be horribly volatile. The only way to remedy this might have to be- to keep it out of in-game. I'll be very interested to see how the devs handle this.
(Can't wait to have a Hawkmoth Heavy VTOL with a flamer firebombs) 