I just fed them some cooked tilapia. Scarfed it up and made lots of appreciative noises.
They get a fermented mash of the feed they pick the grains out of preferentially. They absolutely love that mush and yes, also act like it's a new delicacy every day. Though during molting that's also what they were just not so into. But they're back at it. Even when they were down on food I'd try mixing some of the worms into the mash but even there it was a no-go. But they're back at 50% enthusiasm for the worms I think.
I'll see if I can find a small can of catfood. That sounds like they'd be interested and it would be different. They seem to be not so much picky, but just appreciative of change in their diet.