Would there be interest in adding 0-5 and 0-15 categories? I think 0-5 would be a great entry point, and 0-15 would be another good build to players doing 0-20.

I don't believe either of these categories are required. 0-10 is already a perfectly good entry point and while I don't agree with the inclusion of 0-15 on the GB game, I don't think it is necessary here.

Having a 0-5 is not necessary. 0-10 is a good entry point already. Also, we already have an individual level speedrun which is already additional work for moderators.

0-15 is not necessary. At that point, a player should be at the skill level where they can complete the last 5 levels. Again, we already have individual levels runs that players can practice on.