(Posted this same response in the Discord server): I actually have considered in the past adding an "itemless" category, and I probably would have already except that I can't think of an easy, elegant way to actually add that to the leaderboards.
The easiest way would be to just add a broad Itemless category/subcategory applicable to all levels, but that would leave you with 7 additional "N/A" categories (The labyrinths, the Bonus levels, and WLP) because you can't use items in those, which just makes the leaderboards look messy.
The alternative is adding an Itemless subcategory individually to each level that is made faster with items - which means manually adding 21 different subcategories. That would be the most elegant solution, but it would take forever to set up.
So, I'm not sure about the best way to approach the issue.
My personal opinion would be a general subcategory and accept some messiness in the non applicable categories but if you want to keep things neat then I'd be happy to share the load in creating the subcategory for half the levels if you wanted to make me mod temporarily just for that purpose.
Actually, I'm half-tempted to remove the "1 lap" IL category and replace it with an itemless category (Er, a "No Paw/Cheese" category). There's already messiness with 1 lap, and I'm not sure anyone cares about 1 lap, so replacing 1 lap's messiness with some No Paw/Cheese messiness would probably be an overall improvement to the leaderboards.
i would prefer itemless as a whole than no paw/cheese because other items could still affect the gameplay for the person using them
Other items do affect the gameplay of the player, but they don't make the run faster. They make the run better, though, in my opinion, because they give you a way to mitigate and "fight back" against bad AI rng. You can use shells to hit poop piles or other shells used by the AI, and you can use poop piles to get rid of an AI that's riding your tail. Banning all items, while it does mean you don't need a paw or a cheese to get a good time, it also means you're at the mercy of the AI's rng.