Actually, I had a stubborn Tiger Salamander that refused numerous food items, including nightcrawlers.

That being said, superworms shouldnt really pose a problem as food for a tiger salamander, but I wouldnt feed them a diet of only superworms. Crickets, dubia, nightcrawler should be used as staple foods, with superworms making up a significantly smaller percentage of the diet.

I do not see how poking holes in them is going to make them easier to digest....

As far as mealworms "sucking as a feeder," FIRST OFF, we are talking about superworms, which contain far less chitin and are far more nutritious. Mealworms themselves are as nutitious as you gut load them to be, and their protein content is only slightly less than that of crickets. I would not recommend regular mealworms be fed to a tiger salamander at all.

One should keep in mind that most feeder insects contain chitin, such as crickets adn roaches. I think most insectivorous reptiles and amphibains are equipped to deal with that.