Are Modifiers (ex. Unlimited Multi Jumps, Fastest Move Speed) allowed? Using them can save much time, so I think it should be explicitly prohibited by the rules or divided into different subcategories.

I think they are not but I agree that the rules should specify it

Modifiers are definitely not intended for any of the categories, although I do think they would have their place in a misc category, one that mirrors Portalless's rules, but with modifiers allowed. Do let me know what you think of a category like that. Besides that, I will eventually update the rules for all categories to explicitly state modifiers aren't allowed.

I think its a good idea to have a misc category with modifiers. It could be called "Unrestricted" so that you need to complete the 10/17 levels regardless of any other rules.