At present the altfw feature uses the console font for its menu as a placeholder. This is not suitable for anything other than testing. Instead it should use bmpblk 

From Julius:

I'd really encourage you to look into bmpblk font mechanism, I don't think it would be that much work compared to what you're already doing here. Just adding characters to the GLYPHS string in https://chromium.googlesource.com/chromiumos/platform/bmpblk/+/master/strings/build_font should be enough to make them available, and then it's just about tweaking/expanding the existing draw_text() API in here.