Ability to Bind Extended Mouse Buttons (XButton1, XButton2, Middle Mouse)

In Premiere, it’s apparently not possible to bind any of the extended mouse buttons in the keyboard shortcuts menu.

I understand that it’s called “Keyboard” shortcuts, but there are several standard tertiary mouse buttons/events supported natively by Windows and MacOS, that would be very useful to bind directly.

Specifically I’d like to be able to bind:
    • XButton1 (typically called Backward)
    • XButton2 (typically called Forward)
    • Middle Mouse

All three of these have their own VK codes in Windows already, so I’d hope those would be trivial to make bindable just like a regular key.

I was particularly surprised that XButton1 and XButton2 (aka extended buttons) aren’t supported, as they’re very common on mice these days and pretty universally supported in apps, usually used as backward and forward. They’re described quite often in Microsoft’s documentation, including design guidelines.