00:01:560 (1560|1,1733|2,1907|1) - I think there you're really very clearly following the piano sound here and it's great for filling the gap between difficulty and the most top difficulty but in the next section there are some empty and unfilled piano sounds like here 00:02:254 - and here 00:05:028 -
00:08:843 (8843|3) - 00:11:618 (11618|2) - 00:12:311 (12311|2) - 00:13:005 (13005|1) -
in that part I feel there is an inconsistency in your pattern, what I catch is that you there put 2 notes for the piano sound, for example like here 00:10:230 (10230|3,10230|0) - there it's very clear not sounds like C sounds as you apply that C has 2 notes.
It would be better if you add to each piano sound that I marked by having 2 notes to give the right emphasis to the pattern and song.
the reason why i only use single note at 00:11:791 (11791|3) - and some W like it is that all of them appear when holding the LN
00:13:872 - to 00:15:606 - , according to the rhythm here, double is better to apply for every 3/4 beat imo, 00:13:872 (13872|3) - , 00:14:132 (14132|1) - , 00:14:392 (14392|1) - , 00:14:652 (14652|3) - , etc
00:14:219 (14219|0,14392|0) - I'm marking this because I feel it doesn't fit with what you did after this part, like you put notes then in the next chapter you don't get the same notes in the same column as this is 00:15:259 (15259|0,15433|1) - which means here you should make notes that don't have them in the same column.
That's why I suggest a pattern like this https://osu.ppy.sh/ss/17582090/f9d2 The pattern I suggest contains the same notes as what you made and provides consistency and variety and is more complex in terms of gameplay and of course this course is very easy to hit by veteran players.
you could add a note here since it doesn't really much connect the patterns and it feels weird to play. you could re-arrange this part like this https://osu.ppy.sh/ss/17598441/9375
if you still insists to not add, maybe re-arranging might be ok like this https://osu.ppy.sh/ss/17598451/769b . pretty much either works whether add or not. i get why you dont want to add since that timestamp doesn't really give much sound in it to add a note
00:42:398 (42398|3,42485|2,42571|1,42658|3,42658|0) - don't break your consistency here. do it like this pattern 00:39:797 (39797|1,39797|0,39884|3,39884|2) -
00:46:647 (46647|2,46647|1,46820|3,46820|1,46993|0,46993|2) - re-arrange these like this https://osu.ppy.sh/ss/17598466/5eb7 or anything similar. you used this kind of pattern at the similar tom rolls before and after this part
00:54:623 ~ 00:55:317 - Compared to inside diff, this part seems to be too weak even if it is hard diff.
Insane diff has formed a release for drums and melodies to make a difference, but hard diff has a relatively simple note on drums.
So Insane diff certainly looks full, so I think there's a gap in density. I have two suggestions for this.
00:58:959 (58959|3) - make this a note since all LNs at this section are following the melody synth
personal opinion
01:05:202 (65202|1,65202|3,65375|1,65375|2,65548|0,65548|3) - vs 01:08:670 (68670|1,68670|3,68843|2,68843|0,69017|2,69017|0) -
There is no problem, but if the part expresses only the structure of the drum, I think the two parts have the same structure of the drum for a while, so we can use the same drum expression.
01:26:704 (86704|3,86704|0,87745|0,87745|3) - why not make this a jack? the sounds before are similar so it make sense to make these a double jack like this https://osu.ppy.sh/ss/17598477/f585