I stand mine up on end so I get the best of both worlds.
What about the meat facing down? Won't the smoke penetrate that surface?
I don't know about all your smokers but it seems that in my SnP, the smoke pretty much wafts all around inside the chamber and pretty much touches all surfaces of the meat. Plus on the UDS, the smoke is coming up from the bottom. I do them bone side down and have no problem getting smoky flavor.
And what I really want to know is if there is a pool of liquid sitting in the concave
portion of the ribs with the bone side up, how the hell is it going to baste anything?? If it is in a concave area it isn't going to go anywhere. It will just sit there in a pool.
I sense another "fat cap up/fat cap down", "foil/no foil" discussion with no real definitive answer so my recommendation would be to do it both ways and see if you notice any difference. Then do it the way you liked best.