As a Roblox developer, it currently requires active effort to provide users exclusively using gamepad inputs (e.g. VR/console/controller users) access to toggle Camera Lock (commonly known as Shift Lock) on/off due to the lack of a default binding.
The most easily added default binding to this likely would be ButtonL3, as it currently has no existing default use within Roblox while still being present on most supported gamepad input devices.
The addition of a default binding would remove an unnecessary extra barrier to developers looking to provide a uniform, accessible, cross-platform experience, allowing for developers to focus on improving their experiences without the need to spend extra time manually replicating this behavior for the end user.