I'm testing it and seems to be very broken, typing things around and things jumps everywhere.
I was trying to create something like this too, because I need something that also work for mathematical writing. Let me push a version on github and update, it fixes a lot of issues.
Unfortunately it works on my own version of markdown, which is a subset of pandoc markdown, but I think one can get claude to update the parser to work for other things.
Thanks for trying it out! would you mind giving some steps that allow me to repro the issue? It's early days so i'm sure there are some rough edges, hopefully I can fix them quickly.