Actually, just worked out what it is with that edit thought. I’ll leave it here in case anyone has an issue. It seems that three loop backs IS too many. I added a second label above the first for some of the choices to loop back to instead and no more recursion error.
So yep. Two loop backs maximum it seems.
By the way, does anyone know why the full text no longer works for the random tester? It would have been much easier to find this if I could have seen where it was jamming up at exactly.