Currently the full-width characters are displayed as if they are the same as a half-width symbol, which brings readability issue to CJK users. I have made a new version of glyph_sizes.bin, and I have tested it out in my resource pack, and it seems fixed the issue.

I'll provide several screenshots and my version of glyph_sizes.bin below.

1. The diff. All the changes are made to ff__ code points.
   
2. How they are originally displayed.
   
3. and the after! definitely looks better if you ask any other CJK users.