Can Hex backup be loaded on Hex POE?

I’m planning to migrate from Mikrotik Hex to Microtik Hex POE. Can a backup from the Hex be loaded on to the Hex POE?

No.
A backup won’t work even for an identical hex.
Check this current thread:
http://forum.mikrotik.com/t/backup-restoration-wrong-interfaces/174408/1

That seems like a deficiency. How does one cope with a failed unit if a backup is no use?

Like this.

You don’t have to use my backup system to get practical use out of its documented advice. Take both text and binary backups, supplement the text backup as necessary, etc.