At the moment:
Dongle V2 4G ONLY works with Mavic 4 Pro in the next ways:
Drone:
Mavic 4 pro needs to be on 0000 firmware, 0100 needs to be downgraded to 0000 (fabric version)
RCs:
It works when:
RC 2 with current firmware
RC Pro 2 only with...
You may try, but @Suren and me have tested a period and the dronehacks software isnt detecting the rcpro2 - you will get an error. So at the moment, downgrading is not possible.
But feel free to test and share your results.