In a future version of Dorico we will introduce a simpler way to input arbitrary Unicode characters in the text editor, using a method that is implemented in WordPad and Word on Windows. Try this in WordPad (installed by default on all Windows computers): start a new document, then type 2032
and type Alt+X. 2032
will be replaced by the single prime character.
This is not something that Dorico supports today, but it’s something that will arrive in the next version when it comes.