If they are in deli cups after L4 I would definitely consider getting them into some kind of enclosure where they have many molting options and are not too crowded. Either netting or cage is fine. Or netting in the cage for better molting success.
You may want to take a look through these links. Early on in keeping Idolos, netting and wire screening were found to be unfavorable choices. Neither provides the kind of grip which they require while molting, and it was found to be nearly impossible to keep up the humidity in anything other than a mostly solid enclosure.
I know, it was the same with me ... as I mentioned all went well as they grew. But when my male barely succeeded in his maturing molt because I hadn't properly prepared his enclosure, I began my research. The difficulties which come later on are, I guess, the reason that I got so many congratulations when I posted my matured female, and it took me by surprise. That last molt is a tough one for them, sadly, and it's hard to imagine how they've avoided extinction in the wild, as fragile as they are.
ok... this is what I have my guys in:
and this is another
and my third
I think I need to add Grape vines?
These would be my suggestion. Not exactly cheap but not terribly expensive either. The tops are screen, so they should be at least partially covered to keep humidity in. And here's a good thermometer/humidity guage. I know it's a larger investment than you may wish to make, but these sorts of things really are required for this difficult species.
All of them survived the molt, though one didn't find a proper angle from which to inflate its wings and they dried looking pretty messed up.
