Regarding a blank space in the NWC15 font:
I've just noticed there isn't one. It's hard to position cautionary accidentals and so on without a space; I've wound up using the "extra note spacing feature instead.
I could also use Bach or some other music font, but they don't match NWC exactly.
Anyone found a workaround?
Yep. Instead of using the NWCV15 font to place "text" music, use a font specifically designed for that purpose. Some of them I created myself. Browse the Internet for "MusiSync font" and that might work for you.
.. and on the same page as MusiSync is FretQuik, which you might find useful.
Thanks for the suggestion; I do use Bach, Musisync, and one I did myself for some things, but sometimes I want the visual look of an exact match with the system font - and, of course, when sharing files you can be sure that anyone who has the program has at least the NWC font.
I can see the need for not using an extra font, if you are sending NWC files. For myself, I only need to send someone a PDF document, so I can embed fonts.
But your original question seems appropriate. NWCV15 happens to be using the "space" character for something oher than a blank space. But there are many other code locations (in particular, .0160, where the nbsp is found) where a space could be added. It would probably be best to have a low-width space, for maximum tweakability.
Alas, NWCV15 follows the bad habit of using a box to represent undefined characters. My own fonts simply use a space. The only reason for putting a box would be in critical text documents where the reader needs to know that something was supposed to be there, but is invisible.