Hi
Not sure if this helps you, but a couple years ago I fitted a RNS510 vers B unit HW04 firmware 1100 into my 05 GTI.
Not knowing what vers my canbus was, I suspected it would of needed changing, I played safe and installed modified firmware 2760/1200 and I've had no problems. (No Rosenberg syndrome and no battery drain)
Since then I haven't felt the need to update the firmware further. I've updated my maps as each new version has became available, version 7 with the updated firmware gave 7 digit postcode input, then vers 8 speed cams and I presently have vers 9 7920 maps with speed cams installed.