I found a post, roughly a year old, stating that it would be in one of the next updates.
Well, Updates on this thing are painfully slow and with little documentation; so it might be that it IS being added in “one of the next updates”.
Unfortunately I don’t have proper advice for you on how to rebind it within VorpX, although there ARE rebinding options when you press DEL and go to the section with the Hotkeys.
I haven’t touched VorpX since I’m waiting for an update (atm this thing doesn’t work for the stuff I really wanted to use it for (arma 3)), but I believe there was an option to rebind certain keys internally.
Be careful though (and experiment after applying settings), as the bindings, as many other things, are bugged. In this particular case, certain Keys in the binding are SWAPPED, so you’re in for a surprise :p