Suggest control scheme expansion

Forgive me if possible and I did not figure it out with the current SteamVr control scheme tool

I would like to rebind helicopter collective up (default thumb stick up) to a dedicated button- I notice the (switch seat) button is double bound for index knuckles and I unbound this but couldn't figure how to rebind to thumb stick up
And in the same vein- I think ground vehicles could benefit from additional "actions" in the bind UI (accelerate / reverse)