Supposed to be for a mod4mod, but this map is really quite tight and polished, so most of these will be very, very minor, or stylistic suggestions:
Dusk:
00:21:019 (1,2) - Slight issue with the way these sliders were drawn: Because the curve is very slight, it looks pretty symmetric, but extending the nodes past the slider like this means that they won't actually be completely perfect. Not really a problem here...
00:28:519 (2) - but it causes this slider not to be symmetric with respect to the x-axis.
00:48:769 (2) - Adjust the pattern so this is where 00:45:019 (1) used to be?
00:51:019 (1) - I was surprised that this was not a mirror image of 00:49:519 (4) reflected across the x-axis. Maybe make it like that so 00:49:519 (4,5,1) will have a pattern?
01:18:019 (1,2,3,1,2,3) - Try this instead of the right angles:
02:01:519 (3) - Perhaps drag this down and to the right for a sharper angle in (1,2,3)? (Do the opposite for 02:04:519 (3) if you do this)
Nharox:
Hm... at first I thought Nharox was some fancy name for the a stage of the night I'd never heard of. Maybe rename your difficulties to keep the "Night" theme? Like Twilight, Nharox's Dusk, Midnight or something.
00:39:019 (1,4) - Make the curve flatter, so (4) wraps around 00:43:144 (1) better?
01:15:019 (4,4) - Might look better if these sliders actually weren't symmetric, to capture the total arc of 01:14:456 (1,2,3,4) and the like.
Midnight:
00:19:519 (2,3,1,2) - Trapezoidal pattern feels like it should be something that's rotationally symmetric instead.
00:34:519 (2,3) - Seems randomly unpatterned for a set of maps that are almost completely symmetric in some way at every point.
00:37:519 (2,3,4) - ^Oh, I see that the next set is a rotated copy of the entire section. It's a change from when the patterns were completely visible at the screen at one time, and feels out of place stylistically to me, but it's fine.
Overall, very, very good map! It's rare that a map of this SP is so close to perfect. I'll remedy that with a star + kudostar.
*goes to take a look at worse maps to feel better about my own modding abilities