I purchased these Photo Flips after making my own "additions" to my various styles of Project Life pages (WeR, SNAP, Becky Higgins, etc.) I realized that they were intended for the SNAP albums and not specifically for the PL style pages, but I thought they would work.
And they will, but compromises must be made. The edges on the PL pages are not as wide, it seems, as the SNAP albums these were designed for. I needed to trim-out a bit to make the rings of the binder fit the photo flips add-on. And on other parts of the page, the strip holding the flip on is going to overlap the pock above/to the side. Not a problem, unless it's the "slide-in" side of the pocket page - then it could be a hindrance to adding to your pocket.
The photo flips are well-made and the adhesive seems entirely adequate to the job. Just don't expect a perfect fit if you want to repurpose them for other page styles.
Loved the versatility of this product. Wanted to add additional journaling but did not have room on the page. Added three of the flips on top of the page protector achieved the look and documentation to make a perfect page. I actually hadn't thought I would use the 4x4 size and yet that was what I ended up picking. Will be ordering more...