Something that's always puzzled me about VRChat's gamepad support is that, while there are actions mapped to L2/LT and Square/X buttons, they both use your right hand. It doesn't matter which trigger you press, you'll still grab or interact with your right hand. But it's clear that VRChat does recognize these as separate buttons because in worlds where gamepad support is deliberately coded, there may be functions mapped to these buttons!

I believe each trigger should be mapped to each hand, same as in VR. R2/RT is your right hand, (as it already is), and L2/LT is your left hand. Then, for manipulating items in your hands, R1/RB manipulates what's in your right hand instead of doing nothing as it does now, and L1/LB lets you manipulate what's in your left hand. Then you have Square/X to throw/drop whatever's in your left hand just as how Circle/B does with with your right.

For those using a DualShock 4 or DualSense, (or even Joy-Cons or a Pro Controller?), the option to use gyro to look around could add a level of motion tracking for desktop users similar to how a (shockingly few) number of console FPS games do for more precise aiming, possibly even use controller tilt to lean your avatar's body. I already use Steam Input to have this, but native support could allow for more than two degrees of movement this way.

Also, for DualShock4 and DualSense users, the ability to use the touchpad in some fashion. I personally use it for hand gestures over VRC's official Steam Input mapping of holding R1 and using the thumbsticks since that blocks off use of the R1 button in the few areas where it does something useful such as moving the photo camera. Though not everyone may want that, so options for what the touchpad can do like switching between gestures or pointer control could be possible.