Wouldn't the end-user be able to download it from the cdn anyway? Would an alternative not be to allow them in an open source repo provided that the owner adds a readme to the folder in which the font resides, telling the end-user to refrain from downloading?
Edit: what about an open source non-electron web application? How would they use the font?
Edit: what about an open source non-electron web application? How would they use the font?