Right now, percentage is the only number that factors into the Accuracy calculation,, so there's no differentiation between 300g/300. Therefore, there is only a very tiny portion of the score actually affected by the difference (mainly the combo).This is correct - 320s are very much underweighted because the only component of the scoring system that takes into account 320 accuracy is the combo component, which only has a 20% prominence. Add on to the fact that the difference between a 300 and 320 is so small and that the absolute difference between juan and Hudo's 320 count isn't that significant, it would make sense that 320s are really underweighted at the moment.
You could mitigate this by including 300gs into accuracy, but from what I've experimented it might create too much emphasis on MAX accuracy with charts that players have issues getting 96%+ on (and as a result would not be an accurate assessment of skill). You can try having a weightage of 310 instead of 320 for accuracy instead, but it's up to you.
But by including the rainbow component into accuracy, I don't really see much purpose in having a combo component in the first place, but I'm not quite sure how to justify it and put it in words.
Alternatively, you can avoid including MAXes in the accuracy component and just increase the importance of MAXes to like 360 to increase the emphasis of it by a noticeable but not overpowering amount in the combo component, but that requires a bit more experimentation.
Also as a minor side note: Maybe consider starting the combo counter at max combo? (if possible). That way, it doesn't diminish the weighting of the first 400 notes of the map.Also supporting this.
Also, emphasis on underjoy's post. He brings up a pretty good point about LNs, and it wouldn't make sense for him to have so many misses with a distribution like that. Here's a HRv1 and HRv2 comparison as well for another chart. Given the 50/100 windows of v1, it wouldn't make much sense for the miss count in v2 to be that high in the first place, unless there's some bug that scorev1 has with LNs.