This isn't the answer you are seeking but in my view BBQ sauces are best used to firstly braise ribs in a closed container for an extended period and then opening the closed container - normally foil - for the last 30 to 40 minutes with constant basting with the sauce.

Whilst I've understood the attraction romantically ie in the mind of bbq saucing over coals - I've never seen that the practicalities and challenges of using sauces on an open fire are soluable except to pour over once it's plated. BBQ sauce often has high sugar and/or honey content which will always caremelise and burn faster than the meat cooks - particlarly the cheap cuts used such as ribs. If you are going to marinade then use a marinade that contains no sugars.

Forget the sauce when BBQ'ing except to pour over at the end.