Depending on the size of your grill, place 1 or 2 slabs, bone side down, over the heat and brush the fat-covered side generously with barbecue sauce. Grill the ribs, covered, for 2 minutes. Flip the slab over, brush the bone side with sauce, and grill, covered, until the sauce on the fat-covered side is caramelized and lightly charred, 1 to 2 minutes. Flip the slab over and continue grilling, covered, until the sauce on the bone side is caramelized and lightly charred, 1 minute. Transfer the ribs to a cutting board and let them rest for 10 minutes. If necessary, repeat the grilling and glazing process with the second slab of ribs. Cut between the ribs and serve immediately with plenty of barbecue sauce on the side.