I had not heard of url fragments before. Is there a size cap?

Ish, but the cap is the length of url that the browser can handle. For desktop chrome it's 2MB, but for mobile Safari its 80KB.

The compression algo SDocs uses reduces the size of your markdown file by ~10x, so 80KB is still ~800KB of markdown, so fairly beefy.

Hadn’t heard of it either - very smart, could open lots of other privacy-friendliness-improved „client-based web“ apps