Please be my guest - it wasn't my idea, and what I posted was as far as I can get.
For the animation, I wanted a climb-ladder or a get-in-tank routine, followed by the StandGetOutofTank or whatever it's called where you jump out and away. But I've never used playmove/switchmove, and they seem to lock my guy in place (so I'm not doing it right, obviously).
As to the places where you get the action, it's anywhere in range (check the axes on the trigger), but probably the delay between checks is too long. I find that walking to about a tank's length behind the T55 and then waiting usually gets the menu to pop up.
Also if anyone can fix the behaviour of removing the grenade from the player, that would be a big help.