I set up a nice note spacing in Layout Options. It perfectly works within a staff and within a beamed group of notes (green arrow).
Is there a way how to set up a different minimum horizontal note spacing on the boundaries of the beamed groups or in situations where after a note with a flag a beamed group of notes starts? (red arrows)
Is there a way how to set up a different minimum horizontal distance between notes with leger lines? (blue arrow)
I can see the options for leger line widths but i didn’t find any options for leger lines horizontal spacing. Could you please be more specific where can I find those options?
The idea of the Note Spacing changes is quite useful. I can create two different note spacing changes: one for notes without leger lines and one for notes with leger lines. In Write mode I can copy a note spacing change signposts and insert them where the runs go out of the staves and back to the staves. It is nice, but it is a big job for an opera score… A possibility to define the minimum horizontal spacing between adjacent leger lines would be more elegant. (Something like Gap to Left for accidentals could be helpful.)
As for your comment that none of the options that @jesele mentioned help, did you try changing the value for Ledger lines protrude beyond noteheads in runs of short notes? I do find that playing around with that value affects spacing (I tried with your exact figure on a system that was 97% full).