[diffeomorphism]

If it is only about reading then why not something like auctex preview (shows rendered graphics in place of commands)?

https://www.gnu.org/software/auctex/img/preview-screenshot.p...

or fold-mode (shows unicode and abbreviations in place of commands)?

https://www.flannaghan.com/2013/01/11/tex-fold-mode

Changing the representation seems more sensible to me than changing the underlying file.

Also, while the a/b syntax is easier for easy cases, I shudder to think how a continued fraction might be type set: https://en.wikipedia.org/wiki/Continued_fraction

This seems to make easy things easier and harder things really hard.

Kinda like https://www.lyx.org/Screenshots or using org-mode for latex. Convenient for simple matters and something you have to fiddle with or work around when you want to do anything more advanced.