Speedrun.com subcategories

The KH community on speedrun.com has a unique issue where we have a gigantic number of categories that are very similar due to numerous re-releases with varying tweaks that we've deemed should all be different categories for competitiveness. Because of this, however, it's virtually impossible for us to have nice-looking speedrun.com. In addition, some of the re-releases of the games contain multiple games on one disc, so we have to either have games that don't have their own discs, or deal with super cluttered game pages (see https://gyazo.com/98389c7d283524a303cb1b6cef009e73).

A (somewhat) simple solution that could help us a lot would be to have nesting subcategories. I've created a functional mock of what this could look like here: http://jsfiddle.net/9yr7a06s/2/embedded/result/. I would love to know if this is a feature you would consider implementing and your reasoning against it if the answer is no.

Thanks,
JHobz

P.S. Unrelated: I would also love to see Speedrun.com go open-source on Github as I think there are a lot of places where the code could be polished up by bored nerds like me ;)