Popping in as one of said moderators to say that these functions are already built into the game. The only reason this game is present on speedrun.com at all is because prior to v3, there was no in-game tracking for low% - hence, why the only categories here are low%. As of v3, not only is this no longer the case, but the in-game leaderboard systems are now cross-platform and have a much more robust replay system that has eliminated desync and version compatibility issues. As such, there's really no reason for us to use the boards here at all anymore. They pretty much just exist as a legacy pre-v3 low% leaderboard.
If there's a leaderboard you'd like added that isn't already covered in-game, such as a multi-modifier run (think something like Double Time Phasing Story Mode - layered optional effects like that are one of the only things not tracked on in-game boards), I'd be happy to add it, but thus far the only recent requests have been for any% (already tracked in-game) and high% (which, through every explanation I've seen of what it entails, is either literally just any% again, or is a score run - which is also tracked in-game). There's zero sense in putting in extra work for myself or any other moderator to do what's already handled by the game automatically.
I know this reply is late, but what you described is literally the exact description of any% runs, which are tracked just fine by the in-game boards. Just use those.
Having trouble editing one of my runs. I mistakenly submitted the date as 2013 instead of 2014 on my Descent Trainee Any% run, and though it claims to save my edits, it never actually does.