Remarkable means subscription. And I *DO NOT* want that. If this could support self hosted stuff like Nextcloud or something? Or a simple shared folder?
RSS or Pocket client?
But no, nothing, just the subscription stuff. So it's a no from me.
reMarkable still work really hard to force you into a subscription - or at least into using their very bad, non-zero knowledge cloud service. ... I don't know why but it is not obvious why this would be for the benefit of the user.
I own a reMarkable 2, but I fill it via RCU [1]. I will absolutely not buy into yet another opaque cloud offering in 2025.
edit: The project you linked looks interesting, though!
You have root SSH out of the box. You can run any kind of sync you want. The Toltec repos have syncthing and half a dozen others.
Account and subscription are not strictly necessary for local usage. And there is https://github.com/ddvk/rmfakecloud that allows to sync files without account.