If you enter Audit mode and intend to sysprep, you can make all the changes you need. Then before running the sysprep command, you can upload the image to the Fog server and keep it safe and use it as a āback upā in case you need to revert to a point before you ran the generalize command.
A better solution is to build the image virtually and use snapshots and revert that way.
Either way, you will be able to make a back up before using the generalize command.
I only recommend using the skip re-arm when you are learning to set up your unattend.xml file. But then again using a snapshot, or keeping a back up on the fog server would also negate the need to skip re-arm.
Hope this helps!
Just make sure you donāt upload over top of the āBeforeā image O.O