pdfpc was actually the inspiration for presio.xyz! My main gripe was I don't really want to mess around in the terminal for a presentation and I thought it would be nice to not have to install anything. Presio also doesn't upload any of your content (unless you explicitly share) and it also works if your connection drops for whatever reason during a presentation (the communication happens on your machine between the two browser windows). Also for typst unfortunately pdfpc is only supported as a workaround with some extra tooling and multiple files afaik (https://polylux.dev/book/external/pdfpc.html). If there's any feature in pdfpc that you'd like to see lmk!