The superworm story is bogus. That thing is very dead by the time they get it down.
Wax worms have an awful calcium / phosphorus ratio and crickets aren't very good either. You have to supplement them by dusting with a good calcium powder (preferably calcium carbonate) like RepCal. You have to consider calcium relative to phosphorus because excess phosphorus can impede calcification, a min 2:1 ratio is required. Same like your reef, maybe grind up a cricket and try your Hanna meter on it
Fatty things with better calcium supply are earthworms and hornworms. I've used both blow fly maggots and trout worms as well but I am not sure of the nutritional profile on those. The bait fridge at mowhawk is a great resource.
You should try darts, they're awesome but if you think 2 week crickets are small you are in for a surprise.