I had the same problem with my SLC over 20 years ago.

I gave it to a company that manufactured windshields. They sent it to their plant where they put it in clay and raised the temperature and pressure. The de-laminating and fogging totally disappeared. Unfortunately they heated it too much and some of the fine defroster wires melted.

To prevent moisture from fogging it again, I prepped and primed the edge of the glass with urethane primer and then spread a very thin layer of urethane along the edge.

It was a good thing that I pulled the window when I did as I had a couple of rust spots that were just about ready to creep around the edge where the repair would be visible. The headliner wraps around the weld flange and the factory workers cut the excess off with a knife, cutting through the paint to the bare metal. That is where the rust started.