[doersino]

Very nice!

A while ago, I’ve built something similar on top of the in-browser Markdown-plus-diagrams renderer Markdeep: https://github.com/doersino/markdeep-slides

Aside from things like custom themes and pop-out-able presenter notes, it supports printing to PDF via the browser’s built-in print functionality – perhaps that’s something you could look into. (Maybe you have, but my phone’s browser just doesn’t like it.)