I've found flat and square generally works fine for Commander and Officer sized pistols. For me Government sized pistols usually require a slight rearward rake on the nose to get the cases to get a bit more nose-up attitude so they don't impact the lower edge of the ejection port.
Impact between the case and the lower edge of the ejector port is my indicator that I need to move the contact point between the case and the ejector nose lower on the case.
I don't try to get the cases to land a specific distance away nor do I try to get them to fly out at a specific angle. These just end up being byproducts of the fitting of all the various parts of the pistol most noteably the extractor and the ejector.
If you do need to file an angle on the ejector nose because of impact with the ejection port, use a very small angle. All you want to do is lower the initial impact point just a bit to see if that eliminates the impact. If it doesn't, ever so slightly increase the angle and test fire again. You shouldn't need to do more than a 10 degree angle. Remember, less is more and once you remove metal it's a tough job putting it back.