Unless you use the AVS2 1412 800 CFM carburetor. I'm pretty sure that a TQ's secondary blades will still require an adapter to fit that manifold. I've always heard that the notch is for the three barrel Holley carburetors that were popular at that time.
That is correct, that’s what the notch is for. The mod is also to allow the use of a TQ carb, grinding is for the larger secondaries and the carb will them fit. I have an LD340 intake that’s been modded just like this.