In a future point update, could you add en-dash and em-dash support to repeat ending custom text? It’d come in handy for marks such as “to Verses 3–6” and such. Thank you.
It might be nice if Dorico had tokens for these characters. In the meantime, you can always copy a dash into the Custom Text field from some other document or utility.
(Interestingly, on Windows, that edit box responds in a strange way to the Alt+NumPad shortcuts for special characters and won’t allow entry via that method; it would be nice if this worked as well. But I can copy from CharMap or something similar and paste in.)
PopChar. Indispensable. I use it for everything. Well worth checking out.
Do the usual keyboard shortcuts (for Mac)not work?
EDIT: I just re-read @asherber’s comment re: Windows but I’m guessing it can be pasted from somewhere?
On Windows: Alt+0150, Alt+0151 — and Mac: Option+Hyphen, Option+Shift+Hyphen?
They very much work on Mac. I use them daily.
You beat my edit! 
Belated thanks to all (sorry, jury duty!) for your replies. I know my Mac shortcuts better than my own name, but they don’t work in several text fields, including ending text. I have Ultra Character Map, and perhaps this would be my workaround, but I’d much rather have the capability in-app.