With a larger ensemble, ties and slurs to same note/instrument across a page turn are placed differently, especially depending on staff position.
It appears that slurs from/to ledger line notes have a default solution that is, as yet, not as elegant as the ties.
Yes, I would agree that Dorico’s current defaults for slurs crossing breaks are not as refined as they could be. This is something that we plan to address at some stage in the future.