Hey thanks Mike.

Noel, I will listen to that when I get a chance. You're right, Bbmaj7/C will give you a workable dominant 13 (without a 3rd) but if and only if the 5th (F) is omitted from the Bbmaj7. Otherwise, the F will very definitely turn it into a C13sus.

Bbmaj7b5/C will give you a proper dominant 13 (Fb = E)