Here are a few! There was also a whole wiki, RemarkableWiki.com, for a while where users shared technical tips and tricks. It’s not up at the moment and I’m not sure if it’s down permanently or only temporarily. My experience has been similar to @blusterydayve26@midwest.social — I bought the device because I liked how user-modifiable the software was, but once I had it in hand I found that official development was moving briskly enough with new features and UI improvements that I’ve never really had a reason to mod it. I have SSH’d into the device to set it up with a few of the trickier WiFi networks in my life, though, and can confirm that it’s a breeze.
It really awesome when it comes to reading and annotating PDFs. That’s the main reason I got it — so many e-readers I’ve tried over the years have been horrible for PDF documents and as a professor that’s like 80% of my day. For ePub documents, it’s very capable now — even if that wasn’t the case a few software versions ago. That said, the experience is a bit idiosyncratic among e-reader devices. The Remarkable basically converts the ePub to a static document so that the UI can more or less treat it as a PDF, which is a different user experience than some other e-readers. It’s not unpleasant, but it’s different.