The thing is, there's really no love for the NSE runs in the other NSMB games.
I would support your idea, I just don't think it would get too far personally.
I would like to see a category for this as well, it would be a good medium between 100% and any%.
The medium that already exists as a category, even though it's not added into this website(or NSLU for that matter) is called "All Castles."
I can provide a video of the fastest recorded time, run by HardPelicn:
Even though it's not a NSE category, it's still an extremely interesting run. The only real notable difference with this run, compared to what would be a NSE run, is adding the forest inside Soda Jungle, and maybe 2 extra levels in Marangue Clouds.
Otherwise, the run is pretty much the same.
Hey you beat my time, i run a run with 1:44:37 but i didnt upload it, i think it is possibel to sub 1:30
as much as i am happy to see that the category as been added, technically, you NEED to found the secret exit in the ghost house of the jungle iirc, hence why i though for a while about doing a all castles run instead?! if i'm right, the easiest way to resolve this would be to add an ¤ to the categorie name and state in the rules that it is the only "secret exit" allowed since mandatory... but then again, if i'm wrong, i would like someone to simply tell me how to get pass it w/o using the secret exit cuz i don't remember it being possible!!
The two levels in the Haunted Forest section of the Soda Jungle are impossible to pass without doing a secret exit, which is what would make the category invalid. Posting the rule to allow those would kinda fix it, but it seems redundant.
So, the solution should be re-naming the category to "All Castles" which requires you to go through EVERY world as fast as possible (yes secret exits are allowed), and skipping the first air ship is also allowed, as it's not considered a castle.