On multi-bar rests:
Is there a way to display the bar range under a multibar rest in a part?
Like say there’s a 4 bar rest in the beginning of a clarinet part. Is there a way to display “1-4” under the multibar rest?
Example:
On part specific notation:
In the score I’m currently writing, the Oboe player doubles with English horn, so there’s a key (read:transposition) change that’s specific to his part alone. I want a double bar line on that key change, but I don’t want it to appear in the full score (and other parts), is there a way to do that?
On ties:
Is there a way to have a tie mark that doesn’t tie into anything? I’m writing a bass drum part, I have a quarter note on the down beat, but I want him to let that note ring, similar to this:
ranges on MM rests isn’t there yet…
You can fake a double bar line by adding a text item (shift-x). I just made one from the stem charachter (copy from here: https://w3c.github.io/smufl/gitbook/tables/stems.html paste into D. as text (select music text, upper right of text box) and adapt with font size and font stretch. This will also show up in the score, but since text placement is independent for each layout you can drag it off the page to hide it in the score.
You can use this approach for l.v. ties as well. (maybe this is helpful: Steinberg Forums )
I appreciate the suggestions, thanks! I just tried your suggestions, I couldn’t get the fake bar line to be thick and large enough to ‘blend in’ with the actual barline. And the tie, once I set to the font to be as big as it needed to be, Dorico created a ginormous space between that staff and the one above it, promptly messing everything up. I know that I can just correct that under Engrave, but considering I have that on essentially every other measure, I don’t want to have to reorganize every page manually… unless I’m missing something.
I updated my post with an image of my result… You can switch off collision avoidance of text in Engraving options… maybe that’s an Ok price to pay for the barline … 
I should have thought that, by the time he has to start playing, the average clarinet player ought to be able to work out the number of the bar where he enters!
(Sorry, couldnt resist!)
David