I assume that SD follow what is published by the various national authorities on their paper charts so I wonder if that is the reason why SD now has GAFOR border lines around Paris & Normandy where the reference altitude is so low? Personally I find this just adds to the general clutter and would prefer it to be removed.

Can’t you just toggle them off with Weather>GAFOR ?

GAFOR are forecast areas in France. They are also used in other countries in Europe. They are a useful way of getting a quick update for the weather over a large area. If you don't want to see them and benefit from this information, you can turn them off from the Weather menu.