Just an FYI, for whatever the reason, you can contact LFPB ground from LFPG.
Since the former is a featured airport today, I envision this will happen quite a bit. (It already has.)
Make sure when you’re at DeGaulle you’re not requesting taxi from Le Bourget controllers. They can’t give you the runways at DeGaulle. (Yes, there is a runway 09, but this isn’t a substitute for 09R at LFPG.)
(I don’t know why it’s available, and we don’t need to speculate on that. Just be aware whom you’re asking for what and ensure it’s the correct airport.)
During peak hours, it will be unnecessary clutter for the LeBourget controllers.