20But any operation in OpenType that requires reordering requires a glyphs buffer. This could even apply to Latin if Microsoft really intends to support normalization (i.e. canonical equivalences) in its own USE engine (for now it does not) because it would also require a glyphs buffer to allow correct reordering of glyphs (according to their properties, notably for "beforebase", or for special placement of some diacritics such as the cedilla that moves from "belowbase" to "abovebase" when the base is the letter "g"). Similar complex shaping features may also exist for rendering Latin Fraktur, or Latin medieval texts... Latin is also a very complex script (probably much more than even most indic scripts), as it has really a lot of contextual "features".
Complex shaping is also needed for more correct handling of the classic cursive style, or decorated "swash" styles ! Now with the introduction of "variable fonts" the complexity is increasing (think about hinting, or kerning, and how some glyphs may need non-linear with breaks for example with variable weights). The Microsoft USE engine is still in work, and OpenType will also need major updates to support more scripts (some scripts are still only partly suppported, such as Lana).