2 1/2" to 2" adapters

Like a dummy I forgot about the adapter in the receiver and of course lost it, it was a real pain to find one the road, had to go to multiple auto stores and finally found an adapter that said the the same thing you mention of not to use with weight dist hitches, i had to make due with it until I got home and it seemed to work, I ordred a factory replacement on eBay for $34.95 it has the lip on the end and lines up the hitch pin holes, I think the other adapters like the one I bought in a pinch are meant to be used with accessories like bike racks and others that utilize the hitch receiver, the factory one seems more substantial.