It seems the e-book and PDF support is mediocre on the Remarkable 2. For a note-taking e-reader poor e-book and PDF support is unforgivable. It's a pity as, compared to Onyx Boox e-readers, Remarkable 2 is better designed, built and optimised for note-taking. I think one reason Onyx Boox inflates the price of its devices, other than there is a small number of vendors that sell note-taking e-readers, is their advanced and stable software features for e-books and PDF documents. Boyue has potential - especially as their devices have a similar performance and cost less - but they need to re-design their developmental software.
The question is if the better software on Onyx's devices makes up for the sizeable price difference in comparison to Boyue. I would answer, for the more experienced user, that it is better getting a Boyue e-reader. Boyue might not have the best software, but there are enough third-party applications that can meet most needs. Further, despite Boyue's software being buggy, it is still mostly usable and most key features are supported, e.g. contrast adjustment, highlighting text and typing annotations.