Any ideas/tips to back up the boot drive properly?
If you're trying to protect yourself from data loss, you've already done it right. Making a bootable clone is old school, and modern Macs don't work that way any more. Your backup only needs to contain your data. The system on your Studio is signed and sealed, and cannot be corrupted or broken without rendering the machine unbootable. And if your internal SSD fails, the machine will also not boot.
Read this article:
How useful is the traditional panacea of re-installing macOS in Big Sur? And is it worth maintaining an external recovery disk to deal with problems?
eclecticlight.co
"Given that an external disk attached to an M1 Mac can’t provide Recovery, and lacks key tools such as Startup Security Utility, which can only be run from the primary copy of recoveryOS on the internal SSD, it’s hard to see any value in making an external backup bootable, or in trying to create an external recovery disk. One common reason in the past for preferring a custom recovery disk was to include file system repair tools, such as Disk Warrior and Drive Genius. Currently, no third-party disk utilities can work independently on APFS disks, and those which do so at present only use the same tools available to the user in Recovery mode.
Best practice for an M1 Mac is to ensure that it’s fully backed up, Data and external volumes only, to separable external storage. Should a problem arise which require Recovery, then it should be started up in primary Recovery mode. If necessary, it can then have its macOS container erased, a fresh copy installed, and migration performed from the backup.
Cloning to or installing macOS on a backup disk serves no useful purpose, and just wastes 15 GB of space."