Razer Onza Bumper Jumper

If you have or had Razer Onza controller and were using Bumper Jumper what would you map the two extra buttons to.

Obviously one of the buttons has to go to ‘X’ (to use AAs especially JetPack)
What would you use the second button for
1> Crouching - will be able to crouch longer without having to use toggle crouch
2> Zooming

or any of these Reloading , weapon switch and grenade switching.