FT_Render_Glyph used to be democratic. The renderers were chosen based
on the match between the glyph format and the rendering mode. The only
way to keep it this way is either FT_RENDER_MODE_BGRA or
FORMAT_LAYERED was how I have had originally imagined this implemented (and started even). However, that still makes the GlyphSlot require Face to render, right? Not that I think that's wrong...
The reason I like the current implementation in master is this: FORMAT_LAYERED itself is not enough. We would need a new flag to signal loading layers, since without that new flag, we should just load the requested glyph id. NO_RECURSE cannot be used for this, since that is already used to handle composite glyphs, which the glyph in question might be.
You know that I tried both. We are
introducing new way or rendering (for FreeType) I do not see a problem
with being open and transparent about it.