I wonder, how difficult would it be to do something similar for "Onyx Boox Tab X C 13.3" ? Btw, did Onyx publish sources as required by GPLv3 for that device?

I wonder, how difficult would it be to do something similar for "Onyx Boox Tab X C 13.3" ? Btw, did Onyx publish sources as required by GPLv3 for that device? AFAIK there are no sources in the open (if I am not mistaken ) and I have no idea what can push them toward publishing them.