Anyway, back to the OP...
For ND23B, the only shield I saw in GMSV without the TRUCK banner above it had a TRUCK ROUTE plate below it. I guess I'll add it in as ND23BTrkNew, unless anyone can convince me otherwise.
I should note NDDOT doesn't seem to be a fan of letter-suffixed routes; usand so far has none. ND23A is signed in the field as ND23Trk, and a couple ND200A routes are signed as ND200Alts. IMO this is encouragement to add ND23B as a Trk bannered route. (Even if there's no vanilla ND23B "parent".) I kinda have to wonder whether the 'B' signage in the field was a sign-o.
Edit: ND23BTrkNew added.
Comparison of the branch where I'm keeping these changes <--Dead link removed