Nice arrangement!
I agree with John and Schönbergian on the commas—not necessary IMO.
Speaking of systems per page, I have just been working on an A4 score with 7 systems per page, 6 mm staff size. Earlier music than yours, so less space-demanding, but you should certainly consider following John's advice to make the pages a bit denser.
One other aspect is that the spacing of the music you have set in Dorico's options is rather tight—I think the page layout should correspond to that. So if you want less density, with pages having only 4 systems per page, you could change the music spacing to something more spacious.
It is also a matter of taste whether one wants to use parentheses around accidentals. To my sense of logic, they are courtesy, not optional, so they do not need parentheses (I know it doesn’t mean that, but I’ve been to many rehearsals where people ask if they’re supposed to play the accidental or not if it isn’t completely obvious).
There are some finer notographic details I would correct if I were you. Here is the list:
13:3 RH slur colliding with staff line
23 end, hairpin colliding with barline
26 parentheses almost colliding with accidentals—I would space them out a bit
27 pp colliding with arpeggio
39 bar number could be closer to the staff when there is a bass clef
50 sub. too close to stem
58–59 right slur tip a bit lower to show the direction of the phrase (compare 60–61)
60 pp too close to arpeggio
62 end, why another type of comma?
66 I would keep the diminuendo hairpin full-scale and align it to the first
71–72 mp colliding with barline
71 end, slur colliding with staff line
71—Consider breaking the beams (style of the times!) to clarify the structure and improve the slurs. For instance, b. 73 could have G–G–F–E–F as a phrase with all note stems up and a much nicer slur under the notes, if you break the beam after A5 and F4.
71—To me, it’s not completely clear what you want with the dynamics. Could this be simplified? In my experience (might be wrong), the individual dynamics for RH and LH go under the staves, so I would expect an mp under LH in b. 71 and a p under LH in b. 75, and the mp–pp–mp, etc. sequence under the RH system. But I’m happy to be corrected!
75 and 76 end, p too close to stem
91 voce colliding with hairpin
98—this is something Dorico sometimes does that I personally dislike—the spacing between the first two grace notes should be tighter.
100—see 26
102 end—Is the B♭–D third against the D major chord intentional? Spicy!
105—The slur seems to be scaled down—maybe it would look better at full scale?
Last line—align dim... and pppp
Please feel free to object to what I have written, some of it is a matter of taste!
