It would appear that it behaves like a paint stripper with certain paints, It's highly volatile but there are no warnings or significant directions on the tin. I'll be staying away from it and other U-Pol products in the future.
www.rust.co.uk are supplying me with some small tins of paint to redo the damaged areas. Can't recommend their product Mastic 121 Paint, and service enough. It was news to them that U-Pol's product could do this, even with fully cured paint.