I'm starting to get a little worried now as I also have the 7N0 gateway.
I installed a 7NO gateway in September as I was getting the rns510 but my polar with firmware version 0.2.7 didn't like it as the radio and nav disappeared when scanned with vcds. Without the polar connected everything was fine.
After getting alot of support from polar including a then bespoke firmware that only partially helped, I resorted to reinstalling my old "non RNS510 compatible" F gateway. Everything works fine with no battery drain. The only silent issue I have is a non urgent error in vcds for the nav which works faultlessly. I may try the 7NO gateway in the future but at this time I see no urgent need to change even with the latest firmware supporting 7NO gateways.
1 Fault Found:
01299 - Diagnostic Interface for Data Bus (J533)
004 - No Signal/Communication
Freeze Frame:
Fault Status: 01100100
Fault Priority: 5
Fault Frequency: 1
Reset counter: 224
Mileage: 38265 km
Time Indication: 0
Date: 2000.00.00
Time: 17:42:21