Audioboxer if you update through system settings it can lead to a brick, Shadow updated using Sysupdater with the Native_firm.cia removed, later he installed the native_firm but I would advise against it at the moment.
This is Vappys test payload. It should boot up and when you press a shutdown. The screen wont turn on.
https://mega.nz/#!zpckATrY!lfXwmd_iHyBOPmkH8yLpGrrESIWxOFTsS2iASRD_gwI
I didn't know they made an MSU cart for the Genesis.... I knew about the SNES one and the library for that is rather large but the Genesis one has very few games