Isn't remarkable pro the same size as Kindle scribe? Their website says 10.8 x 7.8 inches.

I wouldn't buy anything from Boox. Notorious GPL violators.

Then don't. You can find flaws with any and every company, but it gets bizarre that such a nit-pick gets commented here every time that brand is mentioned. Most people don't care about GPL.

I mean, I do. I've written some GPL code that actually runs on Boox devices, and I'm quite annoyed they refuse to comply to share back their changes.

If you publish code openly for the world to use, it's not realistic that they'd respect any wishes or demands you make regarding that code. I can make an instructional video available to the public on how to chop wood more efficiently. If I demand that anybody who uses my technique only does it with birchwood, nobody is going to care.