This has been an unfortunate issue for some time now, most notable with fixed wing aircraft and chopper controls. However, there's another issue that is creating a few problems and glitches in vehicle interfaces, mainly in gunner seats that use PiP.

Note: I'm sure this issue with wanting separate controls has been reported already. This is simply me posting another reason (if it hasn't been already as I couldn't find it specifically) as to why this change should be made.

Issue:
For a long while now, I've had my controls set up so that "Optics Temporary" under Weapons and "Zoom Temporary" under View both bound to "Hold Sec. Mouse Btn.". This would allow me to aim down the sights of a red dot or holo sight and focus the camera in on it, allowing me to see through the sight more clearly. When entering vehicles such as the Hunter HMG and manning the gunner seat, I'm able to operate the gun while looking at the PiP screen normally, but when I hold right-click (aka "Sec. Mouse Btn.") I would enter camera view and the magnification of the scope would be locked at Maximum Zoom with no way to zoom out, even when attempting to zoom out manually using the default "- [NUM]" and "2x- [NUM]" bindings for Zoom out and Zoom out[Toggle].

I attempted to fix the issue (thinking that it would require me to use the regular Optics instead of Optics Temporary) by re-binding Optics to "Sec. Mouse Btn." and attempting to zoom out the optics that way. The issue with this though is that no matter what, the Magnification remains glitched and continues to stay locked in the Maximum Zoom factor.

Recommendation:
Personally for this issue I recommend having the Zoom and Optics controls available separately for each list of controls