Bootable external USB

[todivefor]

I have done some further testing noting results:

I did a backup all files with erase. It completed with no problem. I booted to this external, no problem. I safe booted, no problem.

I immediately did a backup all files with smart update. I booted to this external. It goes through the boot process, apple logo, progress bar goes about 1/3 of way, KB lights up, then reboot to system drive. Exact same results with safe boot. When system comes backup, I get message, "Your computer was restarted because of a problem." even though it was shutdown normally. I captured report details and attached.

I have a work around, erase copy, which seems to always work. Let me know if I can gather any additional info.