wow, a type-folio keyboard for remarkable2

[DiTBho]

umm, a few more words about how the reMarkable2 store notes.
Well, notebooks are not stored as single files, they're stored as sets of files.
For EPUB and PDF files, the original file is still in there.
However, there are several files containing metadata.
Plus files containing "pen strokes" for each page.

More info here, about the reMarkable filesystem.

The web interface is built-in as kind of custom web-server that listens on the usb port, on the top of USB-ip, which is kernel-stuff.
Although it is very basic, this makes accessible while the tablet is connected via USB cable, which is really nice and good to have!
You can
+ navigate the same file system presented on the tablet's display
+ upload EPUB and PDF files
+ download your notebooks as PDF files.

This to say, with this simple methodo, "metadata" and "pen strokes" don't travel, but stay on the device 

[DiTBho]

There is also the reMarkable Connection Utility (RCU) project
See here.
It's an utility that lets you manage all your files locally.

Unfortunately (for me), it's binary-only, costs 12USD.
No sources, you buy the binary.