here's some somewhat disjoint thoughts that i somewhat tried to organize:
issue i have with using time as a factor: yes, a 5 hour improve to a 9 hour time is a huge improvement, but how many points is that worth? well, it's a HUGE improve, so it should be worth a lot, right? well... no, because it's still, comparatively, a very slow time, and it didn't improve any ranks. so you award a tiny amount of points because it's still an improve. but... 5 hour improve? tiny amount of points? well that doesn't feel fair, it's such a big improve! but you CAN'T award a lot of points, because then you're going to run into inflation problems.
i'm not grossly opposed to using time as a factor, in fact i like the sentiment. but i don't think it's necessary. the system as-is is already kind of bloated and complicated, but at its heart, it only has one variable -- your maprank. and frankly, in a competitive context, i think that's the only really important thing. yes, it leaves some gaps: maybe SUPER strong records could award bonus points, maybe really close times could award similar points, maybe this or that. but with every new thing you try to address, you're adding more complexity and obfuscation to the system. i learned that lesson while reworking the KSF WR points system: it's hopelessly complex, computationally expensive, and at best, it only KIND OF works.
all that said -- i think there's merit to replacing the "Formula points" element with a time-based element. i think that would be the best way to include time as an element, if we were to do it.
i come from a surf perspective, where times tend to be much more clustered and dense, tending to follow clean distributions and with very few big time gaps between ranks (until you get to the slower end of times). so, improving your PR is pretty much always going to improve several ranks. i understand that's not the case with kz, and maybe other modes as well. STILL, i don't think time-based points are the best solution -- at the end of the day, imo, if i improve 2 seconds on a 2 minute time and don't happen to beat any ranks, well, unlucky for me. and i don't think getting a tiny amount of points for that improve would make me feel very rewarded. (if anything, i'd feel more cheated than i would if i just didn't get anything)
another disjoint thought: i think time as a factor makes more sense in the kz points system, but i also am deeply not a fan of the kz points system, which i feel is incredibly lacking for competitive players. (i.e. rank 1 on bkz_apricity_v3 = 3 minutes, 1000 points; rank 10 = 4 minutes, 950 points. why improve from rank 10, when you'll only get 5% more points? just play more maps!)
one more disjoint thought: within-group scaling is interesting, and i think would be a good way to address the issue of formula points scaling weirdly and feeling pointless. my only issue with it is that it's a lot more complex. but, imagine something like this, a combination of formula points + group points: https://i.imgur.com/i1aCLwM.png
you still get healthy points for improving groups, but you get more points for improving within better groups, to reflect the increased difficulty of shaving off the last few seconds. (imagining linear scaling within groups following a simple rule like 5x for group1, 4x for group2, 3x for group3, etc. but could be played with)
