I assume/think that you will not lose any current functions, although without MFA+ you will be missing the menus that MFA+ has.
The voice control function is also not important if it is available in your radio system, because in a high percentage of cases the system does not understand or interprets your words as if you were an alien, sometimes it's maddening and other times it's fun. ...on some occasions, on long trips usually, I have played with my wife to see/check who was the first/the winner

of the two to enter a complete address (step by step) into the navigation system without making any mistakes... it seems simple, but it ends up being a lot of fun.
In any case, the VW group is the first to sell cars with buttons that do not work.
You have to pay to have that function that the button performs, ...in case you are lucky enough to find a VW group dealership where the technicians know how to activate that function.
