The PC / PS2 version of this game is radically different from the GameCube / Xbox version so comparing times between those two versions is impossible. Is it possible to separate them somehow?

Also, instead of what's labeled as Any% or 100% here I do runs where I go through all twelve races of the four circuits in Obstacle Racing mode (on the GameCube version). If that's not Any% as I've seen it called in the past, would you be able to set up a category like Race% for it?

Oh hey, this answer might be a little bit late. Uh-hum. So I came across the version differences myself. Looks like I am setting up different categories for each version. As it turns out, there is no way to strictly any% the GC/Xbox version since there is no way to trigger an ending or credits of any sort other than selecting them in the menu. So I will decide to just settle with the All Races category as suggested for now.