@Y.D.X No, it’s not proper. Typst selects wrong glyphs while any other software or operating system selects proper glyphs!
Eventually, I solve the issue by a single file (but Typst not):
Arch Wiki: Place SC Chinese before JP Chinese
$ fc-match -s | grep 'Noto Sans CJK'
NotoSansCJK-Regular.ttc: "Noto Sans CJK JP" "Regular"
$ cd /etc/fonts/conf.avail/
$ sudo touch 64-language-selector-prefer.conf
$ sudo nano 64-language-selector-prefer.conf
# see arch wiki 1.2.2.2 section
$ sudo ln -s /etc/fonts/conf.avail/64-language-selector-prefer.conf /etc/fonts/conf.d/64-language-selector-prefer.conf
$ sudo fc-cache -fv
$ fc-match -s | grep 'Noto Sans CJK'
NotoSansCJK-Regular.ttc: "Noto Sans CJK SC" "Regular"
# now, system and every software are proper
# but Typst NOT
Shouldn’t Typst select proper glyph like any other software?
1st 花径不曾缘客扫 // output jp
#set text(font:"Noto Sans CJK SC")
2nd 花径不曾缘客扫 // output sc
/* Perhaps 1st == 2nd should be true,
do you agree?*/