I wish there were better wrappers for it too. One of the projects I'm still quite proud of that I made as a student was a react wrapper around PDF.js used here

I wish there were better wrappers for it too. One of the projects I'm still quite proud of that I made as a student was a react wrapper around PDF.js used here https://boardbook.kent.edu/ https://boardbook.kent.edu/ (though since they no longer seem to be using it I guess it will probably go dead at some point), but the fact there wasn't really a good open source one and as you say the docs were pretty lacking. My favorite discovery was that the performance was much worse unless I registered a particular scroll listener. It's been years now so I only vaguely remember, but I think registering a listener for `wheel` would cause scroll events to be treated as blocking and this made the whole scrolling experience less janky.