Suzuki 2 Strokes

Does anyone know the reason for the large relief requirement on the crankcase side of the transfer ports? The relief shown in the manual is the with of the port and extends to a "point" about .4" below the port.
The second question is what are the ramifications if that relief is not filed or die ground in?

If I've visualised it correctly, the relief is below the bottom of the transfer windows, right? The piston rings will only come down to just below the bottom of the window. I would think just the usual chamfer of the port edges would work.

Thanks for your response.