Since you mentioned it, the new keys that I bound "throw grenade" and "deploy countermeasures" also crash the game.
(Backspace and Home, respectively)
I can only assume that once you bind a function to a key, that 'hook-up' is put into another file, where it is somehow getting corrupted (remembered).
Early on there were problems with binding things to INSERT and DELETE keys, perhaps there are residual issues with the way it was fixed.
Within the game engine, maybe somebody left some development/debug code in there that made use of those keys, and never removed it with the Mantle implementation.
All I know is that when I press INSERT, it crashes every time.
Edit - I can connect to empty servers and throw grenades and deploy countermeasures early on in a round without the game crashing.
(making me think that I fixed it when I make a change to something)
It is when I am in populated servers that the game crashes after having been in the game for a period of time.