Looks good. I've sold a couple similar to that. They were 8 columns by 3 rows like yours, but I have been using 1.5 inch webbing sewn into the front and connected to a ladderlock at the sides with no waist strap. The intent was to carry a load of 6 mags (3 double stacked pouches), and have room for a blow out pouch.
I have one sew up with a GP pouch, a waterbottle/camera lens pouch ,and one of my first aid blow out pouches and it's what I wear when I am hiking.
Personally, I'm not a huge fan of padded shoulder straps on chest rigs. If I am wearing one, there is a good chance I am wearing a ruck or pack over it, and putting a padded strap under another padded strap doesn't feel good for me.
The one in the picture is just a double layer of cordura. I just started experimenting with 3mm foam to add my rigs and give them some structure, and I believe it takes them to a whole new level.
Future generations of my small rig will probably feature cut off corners and a strap attachment system like yours along with a waist strap.
