you could I suppose write a program that continuously scans the buffer and replaces things with unicode, but converts back to ascii on save.

𝕚𝕟𝕥 𝗺𝗮𝗶𝗻⦅𝑣𝑜𝑖𝑑⦆ ⦃ ⦄

> I personally find the lack of highlighting and auto-delimiters is a PITA for HTML/LaTeX though.

Sadly, I have not used acme. Wouldn't this deficiency be simple to overcome with scripting? I guess that's one particular area where emacs, being essentially a specialized LISP interpreter, encourages you to think about these things by default.

Perhaps you could script auto-delimiters. But it has no ability to format the text; you couldn't add syntax highlighting with scripting.