Some suggestions

[Surianto Rustan]

Erwin, I tested it on Notepad & Word.

Does Notepad support kerning?

Fix side-bearing first, then apply kerning for those pairs like AW, or vy where kerning is needed.

Hmm.. maybe I have to review it all again.
Btw, thank you for all the input

[Bhikkhu Pesala]

Test your font in Word, or another application (LibreOffice) that supports OpenType features.