This guy reviews all kinds of e-ink devices. https://www.youtube.com/c/MyDeepGuide/videos

I watched his videos before deciding to get a large format BOOX Max Lumi (13") for PDF reading and note taking. I wanted the large one to split screen a PDF textbook on the left and notebook on the right. That was a few years ago, though, and I suggest reviewing some more recent videos to get an idea of what the current devices are like.