https://bugs.winehq.org/show_bug.cgi?id=7520
--- Comment #33 from Sagawa sagawa.aki+winebugs@gmail.com --- Ah, my patch is for pure bitmap fonts by adding FT_GLYPH_FORMAT_BITMAP case in synthesize_bold_glyph. Possibly, I thought it wasn't useful nowadays or encountered difficulties.
For embedded bitmaps, it seems to be off-topic. So, I'll reply to your mail in wine-devel.