Rejecting this due to multiple points:
* As Jekka mentioned, there's no official rule for it. "BGA option" could be a possibility, but once again - I doubt we could find agreement on when and how this should and shouldn't be allowed
* I'm not familiar with Through the Ages rules, but I assume implementing such a feature would be a pain especially since there are no rules about it
* When you end up in a situation where you would want this, I'd recommend looking at it from a different angle. In Quantum, especially in 3 or 4 player games, it may seem like you have no chance of winning, but you can still win unless the game is a couple of turns away from ending. The fact that the game encourages teaming up against the winning player hugely contributes to that. If you find yourself in a situation where you think you have no change of winning and the game is not a couple of turns away, then focus on making yourself stronger - research more to get better command cards, build cubes instead of attacking the winning player, etc. - and leave the other player(s) to delay or stop the player that seems to be winning.

I've personally had at least a couple of 3 player games where I've ended up playing against seemingly 2 friends that had agreed before the game that 1 of them would win, but not me. From turn 1, they would both attack me, keep destroying my ships and attempt to prevent me from expanding. I remember that I've won at least 1 of such games. So in Quantum you can still win, even if the players intentionally try to make you lose. Just think creatively.