That is a very pretty pouch! I do make mine and I like the idea of making or folding over the front. The only thing I would change if I made these pouches
is instead of using webbing as a strap, I would use a piece of fleece to make the strap to be sure it was safe for their nails. They can get caught in it, or if they are chewers, they might chew at the webbing till it starts to fray.
I would also use plastic links
or dollar store plastic shower curtain hooks instead of metal to attach them to the cage.
If you choose to make them pouches
, be sure your stitches are tight and as with any pouch, watch for loose threads every time they are washed.