Yeah, my husband is mystified by the thing too, because the species of tapeworm that that forms cysts like this have only been found in dogs, horses and cows and he can't find any scientific literature about them being found in snakes. Tape worms, yes, but not this species.
I am so bummed that the vet is booked today, but by tomorrow morning I should know for sure. I probed him again this morning, and "he" definitely probes male. I never popped him though. I really don't like that method because of the potential crushing of a hemipene factor. And he's so big now I certainly wouldn't try it myself. I've had a spider BP and a Jungle carpet sold to me know as females that turned out to be male because the breeder popped incorrectly. I could deal with it if "he" is really a "she" and probes deceptively and has male courtship and mating tendencies...that'd be strange but I could deal with that. Wouldn't hurt to have another female pastel in the collection.