I'm all about experimenting and DIY, but I can say that the vertex diffusers have so many more holes (actually slits) than 50. My guess is that they have about 1000. They are actually designed so that the slits open up just enough to allow your air flow to escape. This keeps the holes from being larger than they need to be. Smaller holes make smaller bubbles and that is supposed to increase water movement.

You have one of those "odd-shaped ponds" that I mentioned and your 2.8 acre pond will require more diffusers than a normal round one. My GUESS is that you will want one in each of the red areas, one in the yellow (far from the red square), two for the blue (one near the island, one at the NW end), and two for the green (one by the island, one at the NE end). This should leave no dead zones. I hope others here at PB will back me up or give reason otherwise as I am just trying to use what little common sense that I have.

I think for experimentation purposes, I would focus on the big red area at the NW corner and do a lot of temp checks as you get further from that area. I bet that the far ends and the strip to the north would get little benefit. What I don't know, should you only aerate the big red square, is...will dead water be constantly created in those coves and migrate too slowly to the diffusers causing a constant mixing of low DO water. This would hurt more than help.

I also think you should reconsider using professionally made diffusers because your pond is so strung out.

I should say that I love the diverse shape of your pond...very cool!