The following code produces a broken PDF.
As mentioned in the code, it works fine when the subset is true. I've tried it with a few fonts. The referenced font is downloadable from here:
Behavior in Chrome: Shows random characters.
Behavior in Mac Preview: Shows selectable whitespace.
Behavior in Acrobat Reader: Shows message on open (Cannot find or create the font 'NotoSans'. Some characters may not display or print correctly). Shows dots instead of characters.
Behavior in Safari: Same as preview.
Tested with 2.0.0 and 2.0.2.
Why does this matter? We need a complete font to embed to use in text acro form fields.