That works well when the strap on the accessory is only 1/2 inch like in your pictures. The HOG utility pockets and the weight pockets have about a 2 inch strap. So for your solution to work I would have to cut vertically through the 2 inch strap, burn the edges which might be a good idea. See picture below.
Hog Large Utility Pocket
The Large Hog Utility Pro BC Pocket is for HOG and other harness BCDs with 2" webbing. Uses velcro to secure the front of the pocket and keep your items inside! Has a 2" inch wide slot for use with any 2" inch webbing! Want to hold it in place? Then check out our weight belt clips in our...www.piranhadivemfg.com
No, you won't have to cut and burn the edges of your pockets mounting straps...just use plastic tri-glides, the larger the better if you can find them (something like this), and use the method outlined in my explanation and pictures. The 2-inch strap on your HOG utility pockets may bunch up a little bit behind the tri-glide but will be inconsequential as it will be fixed in place where you want it, and you will not feel the difference through your exposure suit. If you can find some nice extra large plastic tri-glides, the pocket's webbing probably won't bunch up at all.
I have 4 divers in my household and we all use Dive Rite QB pockets with our backplates and wings....some of the QB pockets are newer and some older, as you noted some of ours have the 1/2-inch webbing on the back and some have 2-inch webbing on the back....we attach them all in the same manner.
Here is a picture of a Dive Rite QB weight pocket with 2-inch webbing on the back, the diagonal piece of webbing, circled in red, is used to orient the pockets in a vertical position on the harness waist belt:
-Z