I am using st. My fonts in fonts.conf seem to be falling back correctly.
This is the monospace block:
<family>monospace</family>
<prefer>
<family>Noto Sans Mono</family>
<family>Sarasa Term SC</family>
<family>Sarasa Term TC</family>
<family>Sarasa Term J</family>
<family>Libertinus Mono</family>
<family>FontAwesome</family>
<family>Braille</family>
</prefer>
When I print a list of folder with non-ascii names it appears like this:
?? ?? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???
?? ?? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???
?? ?? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???
?? ?? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ??? ???