Remap Suggestion
I actually did a lot of work when re-mapping my controller, with multiple tests to maximize efficiency, mobility, and hand movements. Here is what I came up with (PS4 controller)
LB: guardian angel
LT: jump/angelic descent
RB: damage boost
RT: heal
Triangle: ult
Square: reload
X: rez
O: crouch
DpadUP: spray menu
DpadLeft: change hero
DpadRight: switch weapon
DpadDown: coms menu
The biggest problem is that no matter how you slice it, you have to sacrifice one of your analogues while switching weapons (which can be a lot while trying to dodge); I try to switch only when I have cover, while jumping or while using guardian angel.
Hope this helps, give it a shot and let me know what you think 