Maybe consider toning down a bit the usage of soft whistles in the sections at 00:14:976 - and 00:26:976 - ? I feel like they are a bit too overpowering when used every 1/2 blue tick like this, especially in fatfan's diff since it is much more streamy in these sections (00:26:976 - in particular sounds pretty corny at the moment). I believe that doing so would make the more streamy parts stand out more as well
I would use it mostly where the synth is at it's peak like 00:27:913 - to 00:28:476 - and other similar spots and use it less elsewhere in these sections.
i think adding a bridging diff between the insane and top diff would help with the difficulty progression since as of right now, the difficulty jump between the two is a bit too much in my opinion.
the insane diff uses more jumps and sliders to represent the song, alongside only 5 note bursts during 00:08:976 - 00:14:976 and 00:20:976 - 00:26:976, whereas the top diff is a circle only diff with a major spacing increase with 00:08:976 - 00:14:976 and 00:20:976 - 00:26:976 being streams.
same kind of thing for normal > hard, the normal diff is transitioning more from easy > normal than it is normal > hard with it's density.
the hard doesn't use 1/1 breaks to transition from hard > insane leaving the normal to have a major jump in difficulty since the normal is mainly using 1/1 rhythms to bridge easy > normal