i did just have a think about it and made some notes in another thread
This is what you post suggests:
"As far as I can tell the cloning could have been smooth if
-connect usb cable, send m587 with wifi key and ftp enable, get new_ip
-http to old_ip and enable ftp
-download all files from old_ip
-make changes to hostname and ip if needed. (in downloaded files)
-upload all files to new_ip
-run bossac with downloaded reprap binary
-send m997 s1, over usb, to update wifi
-send m587, over usb, with the wifi key again just in case this update was incompatible with the old internal structure."
Does this sequence work as a way to clone the old Duet and copy to the new Duet? Does it work?