[mort96]

This feels like it should be solveable with introducing a few more marker characters, like one code point representing "the following text is traditional Chinese", "the following text is Japanese", etc? It would add even more statefulness to Unicode, but I feel like that ship has already sailed with the U+202D LEFT-TO-RIGHT OVERRIDE and U+202E RIGHT-TO-LEFT OVERRIDE characters...

[fanf2]

Unicode used to have a system of in-band language tags, but it was deprecated https://www.unicode.org/faq//languagetagging.html

[cyberax]

There is a way to do it: https://en.wikipedia.org/wiki/Variation_Selectors_(Unicode_b...

However, it's not used widely and has problems with variant-naïve fonts.

[dudeinjapan]

Yeah. I would have favored something like introducing new codepoints with "automatic fallbacks" if the font doesn't support that codepoint, to ensure backward compatibility. There would be a one-time hardcoded mapping table introduced that font renderers would have to adopt.