I remember feeling this was a little unfair when I would play on the mech, however I would still get screwed because MTF would just wait in front of me as I approached my inevitable doom.
It would be nicer if you can take damage while you're in this state so CI can strategize about regen periods.
Obviously, you would want to take out the biggest threat too. Just like in other games, you target support players to make sure they can't help the rest of the team, or take out the player dealing the most damage then mow the rest.
+Support overall.