I am yet to try run it at all, but had the idea of doing "All Gaps" run of certain levels (similar to GTA V - All Stunt Jumps run). If there is anyone else interested, could we potentially get it added alongside the completion time on the level leaderboard?

Before we go and create new categories, a run must have been completed first. Once that is done, then discussions can begin about adding it.

You're completely right,

Here you go.

And Downhill Jam.

And Mall.

Hey! We went ahead and made a new category on the category extensions board we have: https://www.speedrun.com/thpsce/level/THPS12#THPS12

Don't mind how scuffed it looks on there.

Edit: moved it to https://speedrun.com/thps12ce