I'd like to give you a definite answer, but i'm afraid I can't. But maybe I can help a little bit ;-)
1)
As far as I know every vendor except for
https://www.onyx-boox.com/ sells an boox m92 ereader which is compatible with booxtors firmware. So that's the first argument to try booxtors firmware
2)
If you don't have ivona tts (text to speech) your ereader is quite surely compatible with booxtors firmware because licensing problems because of the ivona tts is the only reason why artatech uses a different firmware (basically it's only the zip password which is different + ivona tts, the firmware is quite the same) So check if your device has ivona tts and if not chances are good that you can use booxtors firmware
3)
You can just try to update, if the firmware is incompatible it just won't update (because of the different zip-password) - I don't think that will brick your device, it probably just won't update.
But in the end it's your decision and your risk to update. Maybe someone else can give you a definite answer or you contact the store where you bought the device directly and ask them...