That's cool. I keep threatening to go back to the torch for a project but probably never will. Too spoiled by now.
I do work my spot welds as I go but there really is no advantage. I just do it to keep busy while the panel cools. A MIG weld is cold by the time you can pick up your hammer and dolly, unlike a gas weld. I noticed Pugsy said he always TIQ welded. I never learned how but have played with a friend's. It is similar to gas welding to the extent you are using the arc to generate a puddle and adding filler to the puddle. Like gas welding you can watch the puddle follow the heat. As I understand it, one of the advantages to a TIG weld is it is softer and easier to work (planish).
Being the impatient kind of guy am, I sometimes will use shop air to cool the panel, holding the air hose 2 or 3 feet from the panel. Once the panel is cool there is no more change that is going to occur so I can move on. Don't miss understand though. It would take me also an entire day to weld that quarter. There is no quick way.
I wonder if in a few years we will be flanging and gluing them. The problem would be hiding the repair. Now there is a subject you should be an expert on.