I think the problems that could arise with managing a 15 acre pond with stunted BG could be overwhelming. Since this technicaly isn't "my" pond I need to take into account what kind of effort the rest of my family is willing to put in. I can't imagine siening this lake to reduce a stunted BG pop.
If there is 0% chance of Walleye spawning then they won't be stocked. It all comes back to the effort, I don't think that they are willing to spend the money or time on getting 6" walleye fingerlings. Already For the initial stocking they want as cheap as possible.
Would walleye have a chance with SMB? What about simply SMB/Walleye/BG? Maybe cut the BG in half and stock 25 SMB and 30 Walleye per acre.
The bottom is going to be varying mixes of sand and clay. And hex. should be able to burrow in the sediments. I spend alot of time looking at mayflies at work, the first time I saw a hex (it was around 1.5-2") I thought "Fish Food!". When do you stock inverts? Before the forage or at the same time?