Page/Subpage versus ControlLayer

I’m currently working on coding a MIDI Remote driver. I am using Page and Subpage to provide multiple mappings for groups of controls. I see that there is also ControlLayer/ControlLayerZone, though I see no description in the alleged documentation.
Can someone provide a brief explanation of the functionality of ControlLayer and how it differs. A link to an existing explanation would be acceptable, as long as it is somewhat correct. :slight_smile:

ControlLayer/ControlLayerZone are to address hardware based paging. Like the encoder groups on the Behringer BCR2000. Best practice is to avoid that, but better using the deviceDriver.mOnActivate callback and send some Sysex or other (manufacturer specified) MIDI message to the hardware that puts it into a “DAW”-mode. Like the Akai APC40, Arturia Minilab and others do.

Ah, I see! So, this addresses hardware paging, not on the virtual surface. Thanks!