Slurs that could be improved by default?

[charles_piano]

If you untick this option, these slurs will always be across both staves (though this can give less good results in some places — you might prefer to leave this Option ticked and to adjust the problematic slurs in Engrave Mode).

Engraving Options > Slurs > Cross-staf Slurs > Determine curvature…

For the vertical collision, we’re probably in a case like described here:

„Resolve the collision..” strange behavior

The problem here is that Dorico does not know exactly how much vertical space the music is going to occupy until it has cast it off, but it cannot know exactly how to cast it off until it knows the height of the music, so this is an inherently circular problem. When the 'Automatically resolve collisions between adjacent staves and systems’ option is on, then Dorico makes an estimate of what it thinks the height of the system(s) is likely to be prior to casting it off, so that it can decide when…

To fix it, you can slightly reduce the vertical margins, slightly reduce the top music frame margin, and raise the top of the music frame a little in the default template. With these three adjustments, I can get 100% fill on this page, and there’s no collision anymore:

Herzogenberg-Nacht-ist-wie-ein-stilles-Meer.dorico (2,2 Mo)