My findings on my first shot at SV’d baby back pork ribs, followed by putting them on the smoker.
I read a couple recipes listed on this site (“Dry Rub, Smoke Finished, Baby Back Pork Ribs”, and “Smoked St. Louis Pork Ribs”).
The first had the ribs cooked at 145 F for 20-22 hours, and the second had the ribs done at 130 F (although 150 F in the directions) for 18 hours.
I put a rack of ribs, cut in half to fit into the SV tub, into the SV tub and cooked them at 140 F for 20 hours. It seemed like a long time to me, but these were thicker ribs than normal, so I went with the longer time of the two recipes suggestions.
The recipes both called for putting the ribs into an ice bath, while still in the bags, after cooking.
I wasn’t going to smoke them for about four more hours, so put the cooled ribs into the refrigerator before smoking. Cold meat smokes better than warm meat, I’ve been told. 
What I found:
The ribs I started with, were labelled as “extra meaty”, which they were.
They also had some fat in/throughout them.
It seems that the 20 hours of SV rendered that fat into a liquid, as after they were thrown on the smoker at 225 F for two hours, they were tender, were meaty, but there seemed to be no fat (which to me, is flavor) at all, in them.
These were done as dry rub ribs, and with no sauce. If you like putting BBQ sauce on ribs, maybe you’ll get the flavor of the sauce, that you want with this method, but I’d rather taste the ribs with some fat and the dry rub.
One thing I would change in those two recipes, if you are going to refrigerate, and later smoke the ribs, is not leaving the ribs in the original sealed bags before cooling and refrigerating. I would drain the liquid out of the bags and put them in a zip lock bag before refrigerating. The reason I would do this is that, when the juices that are in the bag (rendered fat?, and other stuff) cool, they turn into a gelatinous, brown layer 1/8” to 1/4 “ thick, that you later need to scrape off with paper towels or a butter knife, before you can put them in the smoker. It’s a bit of a PITA, which takes time.
I’m not sure I’d go to the trouble of SV’ing baby back pork ribs again, only later to be smoked.
I’ve had better fall off the bone, juicy, flavorful rib results, by simply smoking the ribs for an appropriated length of time, at an appropriate temperature.