Does anyone need an open hardware E-reader?

I’ll be brief. I recently found an open book project online. I liked it, but it seems to me that there are some drawbacks. If I were to do something similar, I would add support for the ePub and FB2 formats, and also make it possible to order high-quality custom cases.

I understand that most likely, to support new formats, it may be necessary to change the element base, which seems to me to be a difficult matter. Therefore, I decided to pretend that the reader from my imagination already exists and made a fake store to present it to people yourbook.xepa.top

Do we need an open source, vendor-lock-free reader that we can solder ourselves? How much should it cost?