After talking to Lippert, I called Dutchman to bring this to their attention. Initially, it sounded like they were blowing me off, but they did say they would call Lippert, but it really took me explaining that THEY, as the manufacturer and THEIR choice which hitch box to use, that they should feel an obligation to know what their choice might create to the buyer (me). Anyway, they apparently called Lippert and said that Lippert apologized for the person I apparently spoke to who they said "misspoke". The gist of the conversation is that installing a capture plate for the SuperGlide does not void any warranty...BUT if a plate were installed to enable the hitch box to attach to a pull trailer arrangement...THAT would void the warranty. Anyway, that wasn't what I told Lippert I would be using it for, but Dutchman assured me that the warranty would in no way be voided if a capture plate for use of the Pull-rite SuperGlide were used.
So, in short and as Emily Latella (Gilda Radner) would say: "nevermind".