I did this because of the damage and resulting uneveness of the underlying fiberglass after removal of the original laminate. I surmised that I would need a good level and even substrate base to properly secure the new laminate to.
The laminate was 3/32". That put it slightly higher than the surrounding frame and I just feathered the edges of it to have it meet the frame level.
There was a very slight gap between the outer edge of the laminate and the inner edge of the frame. That's what I filled. When I masked for painting of the frame I put the tape just inside of that gap and then effectively painted over it so it wouldn't show.
Thanks. I'm going to imitate you on this for sure