I'm back and have figured out
The 2.4G connection + LB/BB + gyro.
Cemu closing & pause button combo works.
Works across your favourite emulators/Steam too.
Using:
v1.02 Beta 1 8bitdo Ultimate dongle driver + activating the dongle to switch mode via "-" & "Y" for ~5 sec until the dongle flashes briefly.
2.4G toggle active on the controller.
Remap controller as PS4 using software called REWASD. REWASD detects the controller as Switch Pro. You just select PS4 Remote Play (2023), select the little wand until the switch controller image, select Virtual DS4, apply to Slot.
You don't need to keep REWASD running. Only open the software to make changes and apply to slot again. You can also remap/load combos etc.
Using the 8bitdo software I remapped the back pedals (L4/R4) to stick pushes (L3/R3). This carried over to REWASD.
The emulators/steam all detect as PS4 controller
LB/BB detects it as a wireless controller but all mapped inputs work including combos from REWASD.
Unfortunately the triggers are not analogue.