Great resource page, Mr. Glover!!!
I'd suggest one more vendor: Chintrackdays.com. You probably know Wei Shen Chin started Chin Track Days as a hobbyist outlet for him and his friends to explore and enjoy the first gen NSXs as they were designed to be driven, on race tracks. The company started out with its principals all being NSX owners, and most continue to own NSXs. Mark and Maria Hicks (who curated the black "Chinnsx" and their own silver, and share the Valencia Red NC, the latest "Chinnsx"), Vince Howard (his gorgeous Zanardi!, and sharing the NC), and of course Wei Shen himself, still rocking his '92 and the 2017 car. (I'm sure I'm forgetting Important People of Chin's history that owned NSXs; apologies.)
No one does track days better than Chin Track Days does them, from quality of instructors, to variety of venues, to format and crispness of how they execute a track day, to safety record, to the awesomeness of the cars they attract (you never know what famous racer you'll see in the Advanced Group; I've been passed by a Dyson Racing IMSA prototype on Sebring's back straight, which started out as a speck in the mirror then WHOOOSH! it was past at probably a buck-ninety!), Jack Baldwin, Porsche GT Cup cars, Ferrari Challenge cars, and others I'm sure I simply can't remember. The paddock is like a moveable car show for sportscar enthusiasts. NSXPO track events are usually conducted by Chin Track Days, and if you've been, you know.
Sorry if you mentioned it in your post, but I didn't see it. They are full-goose NSX enthusiasts and deserve a listing in your wonderfully comprehensive resource post.