Finished! (Took me 3 days)
Private use characters are encoded in Variation Selectors and Latin Ext. D.
GS Unicode is a project I'm working on so (almost) all languages get support! With 14,564 non-spacing characters, this font is finished (as of Unicode 13.0, and as of FS's pre-July 2021 glyph inventory). Please tell me if some of the characters aren't working. I'll try to fix them as best as I can! ...And now, with a new glyph inventory comes a new age....Stay tuned for more updates.