Once again, it is a challenge run. It fits with Odyssey because of how long Odyssey is, and how the Damage system works. With 3D World, there are 500 less collectables, and optimal Any% is already Damageless, and not actually that challenging.

I would urge you to check the other forums as well. Most of these have already been suggested multiple times.

Bowser's Fury Damageless could work as a category, as a lot of the speedrun strats tend to have unavoidable damage if you mess them up, meaning avoiding damage does add a lot of depth to movement. But, it'll need more runners than just Fir_ who did it as a challenge run, not as a speedrun.