Sure we could be proven wrong later but these animals are being sold now and pairings are being planned for next season so we need a best guess informed theory now. The allele theory seems most likely to be right here just like it was with the platy. It took many years for the majority of people, including those breeding them, to come around to the allele explanation for the platy but perhaps some where well served by listening while it was still a crackpot theory. Maybe not the best example because I don't recall seeing the hidden gene being marketed but in this case it's reasonable to assume that soon a fair number of breeders will have access to both toffee and albino genetics and be making decisions based on whatever theory sounds best to them at that time so best not to defer the discussion any longer.