PDF export

[Mapaor]

I know it's a bit weird asking for a PDF export client-side, but what would be the proper way to then transform the HTML into a PDF that actually looks like LaTeX and is everything client-side?

[gosanon]

I would suggest calling print() for an iframe with a document containing LaTeX (or opening a new tab with no UI but with a script with a print() call)
Never done this myself, but might work SO discussion
Another path is using canvas

I used puppeteer to generate latex pdfs from web pages, but it might be impossible in your case since you want client-side export