No you missunderstand me!!
Savemii does the same like savemiifree.Additional it will restore some config files if i remember correct but in most case this dont let you boot back into the sysmenu.And also savemii doesnt let you boot hacked discs.
This will be handeld from the Wii and the System-IOS.Savemii does not flash any files to your NAND eg. custom System-IOS.
If you haved buyed a modchip than you would also be able in use with savemiifree to play your games via Rescue Menu.
Becouse if you set the chip to auto boot it auto boots your main.dol from the game partition.
This is what i altere to make my Rescue Discs.But RM without a installed cIOS 30/50/60/70 doesnt let you boot Hacked Discs.
So you only can boot Original discs.
This is what you to time do.Using RM to boot your games or Backups with antouched signatures.