Thought I'd give an update on my homebrewed wrinkle/blister repair technique from back in 2007. After three years it's totally fine, no signs of new blistering/wrinkling and the repaired areas have been stable. The white acrylic coating really helps keep the roof temps down and that makes a big difference because heat played a big role in making it slip in the first place. Also the asphalt emulsion with knit polyester scrim is proving so far to be a good method for mod bit repair, as long as it's coated. I'm going to use it again on a porch roof which is leaking.