Install dashlaunch and it will block updates and connection to Live! servers.
If you want to use the same unit in both RGH mode and original mode then there is a solution.
I build a slim with a switch. In one position CR is active, HDD active, XD-card in use and iXtreme firmware in drive.
In other position original NAND, original drive firmware and internal 4GB MU are active. HDD and CR are disabled.
Also the switch resets the SMC without the need to disconnect the PSU. The RGH NAND image got different keyvault and MAC address.