To me, the flaring and lowering of the port is not the issue as a properly tuned gun with the original spec port will extract and eject without crushing the brass. The issue is a stock 1911 with a stock ejector and ejection port does not reliably eject a loaded round through the short port. When you try to, the round usually comes out through the magazine well, and I really do not like how a round's primer may strike the ejector as it rattles its way out of the gun. The relief cut at the front of the ejection port facilitates the ejection of a loaded round. If the slide is going to get cut, one might as well flare and lower the port while there as it can provide margin for clean ejection.
Apologies for the old thread bump, but I just wanted to thank everybody that contributed to this thread who talked me out of buying that Kimber. I ended up going with a black Dan Wesson Valor--had to throw some trade-ins at it first but I'm glad I did, and even more glad that I didn't make any impulsive decisions that I was considering when I started this thread.
Thanks again guys