Having shift-click for range selections would be great.
Speaking of that, in Dorico you can already use shift-left and shift-right to extend the selection to left or right. This is same logic as in Sibelius, but despite using it for years I still don’t find it super intuitive. Have you considered using “word-processor-style” logic instead?
Here’s what I mean: Let’s say I’m selecting characters in a word processor, and I accidentally press shift-right one extra time, and make my selection too large. No problem, I just press shift-left to cancel it, and all is well. In Sibelius - and now, in Dorico - I also instinctively press shift-left. But now my selection is too large in both directions. At this point I usually give up, and start my selection all over again. In a word processor, shift-arrows and shift-clicks don’t actually extend the selection, but move the “most recent end” of the range.
Of course, it’s actually not quite that simple, because Dorico’s selections can be more complicated than just ranges. In fact, a better model to copy could be how file selection works in Finder (Mac) and File Explorer (Windows). I don’t even know all the corner cases they’re doing, but somehow they have managed to combine Cmd-clicks and shift-ranges in a way that does what I expect. In fact, it works so well that when I use it I don’t even notice that they’re actually doing something quite clever. Roughly, I think that shift-arrow and shift-click move the most recent end of the most recently selected contiguous range or something like that.