Does anyone have a workaround to get backblaze working? The installation process moved /.bzvol to /System/Volumes/Data/ and backblaze still expects to be able to write to root. I'm guessing you could create a firm link from /System/Volumes/Data/ to /.bzvol but haven't tried that, if it's even possible using command line tools.
Backblaze not working due to read only root
You could try to disable SIP and create a symbolic link /.bzvol -> /System/Volumes/Data/.bzvol