I spoke with my friends about making a xoconostle salsa and according to them, I got most of it right except when it came to the skins.
Apparently at least in Hidalgo, they also incorporate the skins into the salsa when they are pounding it with the molcajete. They tactfully said my version would be good but it would be a little odd not to incorporate the roasted skins as well. Another reason to slowly roast and rotate and not allow them to burn.
Back to the Mexican grocery store!