I’ve also read about a Z-Machine interpreter called Folly that runs on Remarkable 2 Linux tablets and allows handwritten input of parser commands (I believe it also requires installation of the Toltec package manager, but don’t quote me).
The Remarkable 2 tablet is a nice piece of hardware and I’ve always wanted to try Folly out but haven’t made the time to do so yet.
I never heard of Onxy Boox but I love the Boox Palma 2’s form factor (sometimes a tablet is just too much). I wish Remarkable came out with a design like that.