I see the great minds think alike

Your method seems alright to me. With the exception of the missing step 5 in the third post in my thread, but I cannot see how that might have made a difference since BabkupMenu wipes both rootfs and optfs anyway before restoring the backup.

However I found that restoring a backup on another device may be a bit of a hit and miss. Currently I am employing a bit lengthier approach: stock reflash, update, upgrade kernel and CSSU, install and remove apps as necessary, copy personal data. It takes a few days but works every time, unlike the restore-from-other-device's-backup way.