[granda]

Are there any downsides to me using this to build my own archiver?

[nikisweeting]

Many projects are already using this for archiving purposes. Check out https://github.com/pirate/bookmark-archiver

It's robust because the modern web is pretty much built for Chrome, although it can be resource-intensive if you're archiving many sites.

[xfer]

converting to pdf is lossy, i wouldn't use this for archiving purposes, normally i use webrecorder for archiving.