I bought two juruense cats from Snookn21 (John) a week ago at his place and had a nice conversation with him. He said that small juruense are nearly impossible to wean off live. He tried great many times and failed, even though he uses excellent Hikari stuff (which reminds me - when you offered yours some pellets, did you offer Mascivore?). I don't believe John ever tries frozen fish/shrimp/etc, but I may be wrong. He said they do take blood worms and earth worms sometimes, but not consistently.
He also said that they need to be bigger, I am guessing at least 10" before one can safely try to fast them long and hard so they accept dead/dry foods. Otherwise, he says the small ones would rather starve to death. The ones I got from John are about 4" and I am following his advice of just sticking with live guppies for now. So I catch the guppies in my wild outside ponds then quarantine them while treating with praziquantel and metronidazole (prophylactic doze) and then give them to my little jurs.
Any news on your front?