[Question] - Where is the code responsible for setting the buttons to toggle TPV On/Off

[Morsmalleo]

I would like to have ago at seeing if I could bind the functionality to toggle Third Person View On/Off to the Left Thumb Stick (L3) Click rather than using L1/LB + Triangle/Y.

As far as I know, the Left Thumb Stick Click isn't used in the game at all, which serves as a perfect Toggle Button for the MGS2SoS Mod, similar to how TPV could be enabled and disabled by clicking R3 on MGS3: Subsistence. The only difference would be that L3 toggles TPV instead of R3 since R3 is used for the HF Blade Stab in MGS2.