Just for the record ... in several youtube videos
, it has been demonstrated that the stylus delivered with "PocketBook Pro 903" is compatible with "Onyx Boox M92".
In another youtube video
, they use the same stylus with both, the "Ectaco Jetbook Color" and the "PocketBook Pro 912".
So, all of them should be compatible with "Onyx Boox M92".