I don't have a pellet grill but just to give you yet another optional tweak to an already great cook...
SWMBO likes glazed/sauced, fall-off-the-bone ribs; I prefer a bit of "tooth" and am happy with or without sauce so I cook two racks at a time and, during the wrapping phase, stack them (meat side down) in the same foil with butter/honey/brown sugar/rub on the bottom, between racks, and on top.
The bottom rack gets more "juice" and braising than the top and ends up perfect for her (and you probably won't need or want to sauce during the final phase); the top rack is a bit drier and less sticky/sweet - perfect for me.