Jake, I guess the point becomes--since we're shooting at game birds, and since we're supposed to be hunter/conservationists--if you don't advocate it, then why do it? If I want a pheasant dinner that badly and I can catch them on the ground at 60-70 yards, I'm going to snipe them with a .22. Much more effective.
Yes, there are 3" loads that go faster than 1200 fps. And you'll note that all those loads have less shot than the 2 ounces I specified in my post. So . . . to gain speed, you're losing pattern density. Since the 2 oz load does retain sufficient energy at 70 yards, why would you want to give up pattern density--which is your real issue at that excessive range?
The people who have analyzed what it takes to kill pheasants suggest that you need a minimum of 2 pellets in the bird's vitals in order to ensure a clean kill. That's an area of about 17 square inches. So shoot some patterns, whatever loads you wish (as long as they're 4's or larger--nothing else retains sufficient energy) at 70 yards. First, see how well you're able to center your pattern on your aiming point at that distance--by mounting and firing as if you were shooting a bird, not by aiming the gun. (And remember, of course, it's going to be harder to do that on a bird in flight than on a stationary target.) Then cut out a circle with a diameter of 4 3/4", representing the vital area of a pheasant, and look at how many places in your 30" pattern circle you can place that small circle, where it won't get any hits at all, or maybe just 1. And how many places it will get at least 2. That might give you second thoughts about shooting 70 yard pheasants--assuming that your interest is not in making an occasional lucky kill while crippling a high percentage of the birds you do hit.