Re: live-snapshot question (2)
Ok, I've got things working properly now. I found that one of the bugs I was hitting was fixed in newer versions of live-initramfs (#565456). The newer live-initramfs also had a new option called "live-media=removable-usb" which tells live-initramfs to only search removable usb drives for the root filesystem. (Not sure if it restricts snapshot file searches to the removable usb drives as well.)
So, I pulled the latest from git and built and installed live-helper and made my version of live-initramfs availabe to live-helper as a custom package and now snapshots are working as I expect.
Here is the boot parameters that I now boot with and work well for me.
noautologin nouser persistent quickreboot live-media=removable-usb
Thanks for the help Geert.