Weird issue with AFB

Sorry,
Not following this at all.
[1] Pic in post #10 shows a port below the blades [ at idle ]. This will supply manifold vacuum.
Why was it necessary to gouge the hole as in post #12?
[2] You can Tee into any man vac port, except PCV, to provide man vac for what ever accessory you want. So not understanding why a you had to drill a new port when you had one already?
[3] Are you using manifold VA?