RC, let's wait and get input from folks with experience in your general geographic location. However, my first thought is that your bluegills are still young, and you need to see if those first stockings make it to at least 10 inches or a bit more. If not, then you might want to consider more intense management. Given your feeding program, I am guessing that you just need a few more years.
Yes, it is amazing how fish can really start to stack on weight as they grow. You probably recall that Lusk and I had a bluegill standard weight table in the March/April issue of Pond Boss magazine. Below, I repeated the weights at various inches for bluegill -- you can see how weight goes up so much faster than length, so a good example to share with everyone
6 in = 0.16 lb
7 in = 0.27 lb
8 in = 0.42 lb
9 in = 0.62 lb
10 in = 0.88 lb
11 in = 1.21 lb
Plus, remember that these are just the standard weights to achieve a relative weight of 100. Given that many plump bluegills on fish feed can have relative weight values of 130 or 140 on average, you can multiply the weight in pounds times 1.4 and see just how plump an 11 inch bluegill might be (1.4 X 1.21 lb = 1.7 lb)!
