In truly 50/50 mixed bag country like I often hunt, I will load my semi-auto for pheasants and have quail loads in one pocket of my vest. I don't go quick on the trigger for quail on the covey rise anyway. I want to be able to see how many are there before deciding if I want to shoot at any. If I shoot one late on the covey rise, that's fine, and I can reload my gun with quail loads before pursuing the singles.
The appropriate load for each bird probably works best, but I have shot plenty of pheasants stone dead with quail loads and shot plenty of quail with pheasant loads and not torn them up at all.
If you have 5's, let the quail get out a bit. If you have 7.5's, be quicker, and have the discipline not to take a long shot on a pheasant from straight behind. :cheers: