Here’s a video to demonstrate the 2nd scenario I describe above, where attempting to drag multiple chord symbols at once results in irreversible deletions (and the result when I try to CMD-Z each move):
It seems that there are a few behaviors that, independently, are fairly reasonable (dragging an object in write mode is actually moving the object in real time, an object moved on top of another object overwrites that object, dragging multiple items at once is apparently not supported), but combined, these result in a pretty hazardous situation.
To summarize (in order of decreasing importance):
I can see no justification that dragging anything should ever result in content being deleted in a manner that can’t be undone. That’s a bad user experience, plain and simple.
I think most users would expect that dragging and dropping could be done w/o items in the path being affected. Can you imagine if Finder worked this way? What other system requires you to be careful about where you drag when moving elements around?
I would expect that dragging while multiple items are highlighted would move all those items at once. Though, I could see why this might be technically somewhat complex.
I hate to say it, but Competitor F handles dragging and dropping quite nicely: You get a nice highlighted rectangle around wherever you drag, showing you exactly where you’re about to drop and how much space the resulting paste would take up, and you can move that rectangle anywhere you want without worrying about deleting anything in its path. And of course, you can always undo anything you move. I’m not suggesting that Dorico needs to do that exactly, but I think the 3 points above are reasonable expectations.
As always, I report bugs and write long posts like this because I care, and because the Dorico team has shown such care in crafting a beautiful piece of software and being responsive to user asks Keep up the great work!