I've seen a number of posts where people have had challenges on their M1 Mac when reinstalling the OS from scratch or reformatting and reinstalling the OS or erasing their M1 Mac to return it. As of Big Sur 11.0.1 - doing this the traditional way, using the Recovery Tools causes issues (Using Disk Utility to erase or reformat the hard drive and then reinstall the OS).
I found a simple but obscure method/option that works and leaves you with a clean install of the baseline/clean OS and no bloatware (iMovie, Garage Band, Pages, etc - you can install them later if you want).
With Mac OS 11.0.1 here are the steps I used to successfully Erase my M1 Mac and reinstall the baseline OS:
1: Shut down your M1 Mac
2: Press and
hold the power button down to enter recovery mode
3: Click the "Options" Gear-cog icon and then press the "Continue" button that appears below it
4: On the next screen,
STOP. Look to the upper left corner - to the right the Apple Logo in the menu bar, select "Recovery Assistant" (it is the only menu item)
5: In that drop down menu, select "
Erase Mac..."
6: Follow the on-screen steps from there
Note - you will need wifi access. From what I can tell, using this process completely reformats the Mac hard drive to a single partition, downloads a fresh copy of Big Sur, creates a new recovery partition and a new OS partition with an OS
only install (no Garage Band, iMovie, Pages, Keynote, etc - which you can install later). The process took about an Hour and ten minutes.
After the OS re-installation is complete, your Mac will restart to a setup assistant. If you're
selling, trading in, or giving away your Mac, press Command-Q to quit the assistant without completing setup. Then click Shut Down. When the new owner starts up the Mac, they can use their own information to complete setup. Otherwise, follow setup assistant and
Welcome to your clean Mac with no bloatware.
The obscure "Erase Mac..." selection in the Recovery Assistant drop down menu is the easy button to wipe/reset your Mac's OS.
