Cross Hotbar addition suggestion

Currently, when holding down a trigger (either L2 or R2) which enables you to use actions with the D-pad and ABXY/cross circle triangle square, L3 and R3 (left thumbstick button and right thumbstick button) are disabled. Meaning you cannot switch between engaged/disengaged and first person/third person (assuming default controls) while holding a trigger down. However, while a target is selected, L3 (assuming default controls) is target lockon which does work while holding down a trigger. What I am suggesting would conflict with that, and I will continue this thought further down. I would like to propose the ability to execute more actions with L3/R3 while holding a trigger as displayed in the below crudely put together image:

http://i.imgur.com/cZkVbwT.png

To allow the choice of target lock or additional actions, I would also suggest having the L3 option and R3 option for the above image be separate, that you could enable R3 actions while leaving L3 to be target lockon.

Thank you for your time.

PS:If you could allow for complete customization of the controller in Button Configuration, that would be great.