There is no such thing as an approved vendor (nomenclature is important as to not imply that armor from any vendor will automatically be approved) but a few that have been vetted to provide consistent, high quality product. Lots of great makers aren't on our lists either.
There are only two makers of full Rogue One style TK armor at present - Jimmiroquai out of the Phillippines whose fiberglass armor is very accurate, and 850 Armor Works out of Florida, whose ABS armor is much softer in detail due to the material and less accurate, but improved with a recent update.
WTF appears to be creating molds for kits in the future, but the jury is out on quality until complete.
You're correct that there's no way an OTTK would pass, even at basic for this costume. Just too many differences.