This also involves a restructuring of the handling of glyph lookups from GSUB since Ligature Substitution can result in many glyphs being replaced with 1 glyph, and future looksup may result in one glyph being replaces with many glyphs.
Modern fonts expect this and the presentation form B glyphs are a fallback.
Reduce bidi duplications from gdi32 by using the newly corrected usp10 functions.
Aric Stewart