See:
https://news.ycombinator.com/item?id=13962242 (lots of comments)
https://news.ycombinator.com/item?id=34491562 (recent post)
Should TeXmacs support ascii math for easier typing and importing (e.g., from a ChatGPT response, a forum answer, etc.)?
Haven’t really seen AsciiMath be used anywhere and script parsing it doesn’t seem easy to port to Scheme. (Though Guile supposedly can run JavaScript so maybe don’t have to.) Since mentioned in second link, supporting the LibreOffice Math language (probably even more work) on the other hand could make TeXmacs attractive to students using LibreOffice for homework and similar.