You'll need the VE.Direct to usb adaptor to change settings in the mppt, but VRM can manage firmware changes in the mppt without it. And you'll need to pull the existing cable from the mppt to do it.

That's the opposite way round for the Multi, and an 'anomaly' in the system..

If you have an internet connection at the CCGX you can use Remote VeConfigure via VRM portal to download/upload config files from/to the Multi.

But I would recommend you to update the firmware of the Multi and that can only be done with a MK3.