Supernote hasn't posted anything about the potential future Linux system. I'm personally not expecting this to actually come around.

The standard OS is derived from Android, but has no Google Play services and only supports side loading (which works well via ADB; I've not tried other app stores like FDroid). It doesn't have a lot of standard Android things like a home screen/launcher, no notifications, and no UI for switching between apps other than using the sidebar to bring up the application list and going back that way. There are no speed modes for adjusting refresh rates.

IMO, it's a great eink notepad & sketch book, and makes a good ereader with something like koreader, but it's not good as an Android tablet.