Here is my experience for ruffed grouse (sorry not pheasants) and I have logged a lot of hours behind a lab in the grouse woods.
I believe Sit to Flush is not critical in the grouse woods. The woods are pretty thick, the birds generally flush, get up quick and are out of sight. The dogs don't tend to chase like they would in an open field. I don't think I have ever fired two shots at one bird in the same flush. It is one of three scenarios. 1) Wild flush and neither dog nor hunter sees the bird. Any follow up is based on locating by sound 2) Flush with missed shot or no shot at all, follow up on the bird 3) Flush and bird shot, retrieve.