Regarding volume changes in 1/4 rhythms:
Parts before kiai, I think 30% might be too quiet for an active rhythms, consider buffing it to 40% at least?
For kiais you use quite a huge jump in volume like 01:13:806 (drop by 40% here), 01:18:707 (30-35% further), such jump in volume might affect gameplay badly cus of the sudden loose of hs feedbacks. Consider removing these volume drops or nerf them to not higher than 20% (90-70, 95-75), which still keeps your idea and doesn't affect feedback that bad.