(anon451647 writes)
This line (in PrintDraftChanges.txt) will change a plus sign to a thin space if it has a non-space character on both sides:
"(?<=\S)\+(?=\S)" > "\u2009"
We could use \w (word forming character) but sometimes if a language has letters that aren’t in English words \w does not match them (especially if they are non-Roman letters).