Jon, most of the 28's we're shooting are modern, which means less worry about pressure. Different story, of course, if you have something like a Brit 28ga. Or a vintage American 28ga. But not very many of either of those out there. Pro Reach gives low pressures, but you have to use a lot of it, and the velocities are quite high. If the goal is to protect old guns, it's going to result in an increase in recoil, which may not be what you want. I know that when I go from standard AA factory target loads to the sporting clays version, I have no trouble noticing a difference in recoil in my 5 1/2# Parker Reproduction.
