Very good idea!
Sven said in an interview, that people will be able to recreate their DnD characters in BG3, and I really hope Larian delivers on this. So far it's not possible, as they strayed a bit far from DnD 5e for my taste, but we will see what the next patches have in store for us.
Anyway, your idea sounds really, really great, not only would I be able to import my character into the game, I can also play my BG3 character with my friends at the table 😁