Libra Chinese characters in majority-English texts

[kjulia28]

I have some books that are in English, but that include Chinese characters both in the text and in footnotes. (Cultural explanations, names, etc.) Initially I didn't get to display these characters on my Kobo (Kobo Libra H20) at all. Having some some research, I got as far as:

1) Switch the whole book to a Chinese font (NotoSerifSC is what I ended up using); Chinese characters display fine, but now the English text has lost formatting such as italics and bold, and I also don't find the fallback for Roman letters not as easy to read. (It also seemed to crash the Kobo quite a bit, so switching whenever I notice a missing character just to check what the character is doesn't seem like a great solution either.)

2) Convert the individual books to kepub, which as people on this forum helpfully explained is able pull missing glyphs from other native Kobo fonts. This is now better, as at least some of the characters are showing, but the two fonts the glyphs are pulled from ("Kobo Tsukushi Mincho" and "Kobo UD Kakugo") are Japanese based and obviously don't contain all of the Chinese characters.

Is there any way to tell the Kobo to pull missing glyphs from an additional font, or even its native AR UDJingxihei, instead of from Mincho or Kakugo?

The scenario I'm looking for is that I can set the font for reading the majority-English texts to my preferred font (Bookerly) that maintains the formatting like italics and bold, and have the Chinese characters substituted from a font that contains Chinese characters. It feels like the kepub "pulling characters from Mincho" is SO CLOSE to the solution, but not quite, so I find this quite frustrating.

Is there any other way I could tackle this issue that I haven't found yet?

[agugu]

use Fontcreator ，and choose the fonts shape you like(you need find some GBK/GB18030 fonts which contains enough simp and trad chinese characters as far as possible),
Two method below
1.rename font-family name as "KBJ-TsukuMin Pr6N RB" and "AR UDJingxihei"(file name:KBJ-TsukuMinPr6N-RB.ttf,ub_arudjingxihei.ttf),move 2 files to sys path "\usr\local\Trolltech\QtEmbedded-4.6.2-arm\lib\fonts"(SSH,or make your own koboroot.tgz)
Maybe you can move the 2 files to storage path（X:\fonts）

2.or combine the chinese characters with your English fonts,put it to X:\fonts