I transcribed this in Sibelius. It is not horizontally spaced entirely as I would like, but it only takes up half a page.
I imported the score into Dorico as a MusicXML file and the result is as below. As can be seen, six bars take up a whole page, and what was 11 pages is 28 pages in Dorico.
I have tried reducing the crotchet spacing to 2.5 and removing all but the first flag; but that doesnt work.
If anyone here is used to dealing with such problems, I should be grateful for help.