If I well understood, your new version of payload_dumper reached to do the new images ? If so, I’ll post my script to get the OTA update without the phone here : FP3 : MITM update engine and we’ll be able to have any new version of the stock rom 
Also, it would be nice to add a link to the bsdiff and puffin repo on the readme. OK, i’ll use git clone --recursive next time 