Originally Posted by HarryT
Is there any reason to suppose that the firmware wouldn't be interchangeable? On earlier Onyx models that were rebranded by other retailerss (eg the Onyx Boox 60, which was also sold by BeBook as the BeBook Neo) you could install whichever firmware appealed to you.
Yes, some retailers customize the Onyx M92, like one that change the TTS software and lock the device. It's interesting to check if the device accept the standard firmware.