These require lots of composite glyphs, and stacking diacritics. Designing them to fit above the capital letters without increasing the WinAscent too much takes some skill.
- Add all of the characters needed with the Transform Script
- Add guides and increase WinAscent for the first one
- Recompose the stacking diacritic accents, and make simple again for editing
- Design the accents to suit the font
- Recompose the Vietnamese Characters.