Default font for missing fonts

I’m looking for a way that any word document I open with a missing font will use Mistral as the default replacement for the text in that font.

I know I can do the font mapping but that only works once I know what font I’m missing so I would need to be updating that mapping table continuously if I find a missing font.

Is there a font mapping that would allow me to do font = Everything Unknown map to Mistral?
I tried to set the default English font but that did not work either.

This needs to run command-line in a Linux container to convert word documents to pdf.

Thanks

IMHO this could be configured in the OS or the font renderer because missing font is detected there. You didn’t mention your OS (I have absolutely no skill in W$; I know this is possible in MacOS and Linux).

This would need to run command-line in a Linux container

Font translation at this level is handled by Linux, and again you would need to know the missing font name. I have recently gone down a rabbit hole regarding fonts, particularly in how everyone specifies their own fonts these days and there is no easy mechanism to apply preferred fonts (especially for accessibility reasons). I really think devs need to start thinking more about this rather than branding content with their own styles and ignoring accessibility for end users. Sorry that doesn’t answer your question, I hope there is an easy answer.

This StackExchange answer may provide the solution you’re looking for.

This is not exactly what you want: the answer overrides the font for designated ranges.