They aren't really a dwarf form of BCC/BC/True Red Tail. They just don't get quite as large as other localities of BCC/BC/True Red Tails on average. As for Nicaraguan Boas, they aren't considered red tails and are a completely different species, Boa imperator. Though other species/subspecies of boas can have some degree of redness to their tails only Boa constrictor/Boa constrictor constrictor are considered True Red Tails.