While it does say it is independent of FBW I have found on my testing that it still uses the global FBW “options” so if you change any option such as simbrief username, control config ect it will reflect in this aircraft.
The fuel issue I found while tinkering looks to be related to lbs vs kgs. If you have .70 of FBW installed you have to load it up set it to kgs and then the fuel should be correct in the A330. However as stated this does not use .70 FBW yet and the setting went from MCDU to all EFB. IF you install the 06.3 version you will get the MCDU option to change from lbs to kg in the A330 without having to load the FBW first. In my testing I also found that changing from lbs to kg, restart the flight and then change back to lbs and restart it will accept lbs input.
So yes while it is independent of FBW version it is not 100% and if you change any of the user options that were present in 063 FBW it will be reflected across both.
Again these were just my individual testing observations, I am in no way associated with either Dev team but this may help others or maybe a dev will chime in about the FBW user settings file that both appear to share.