George,
Understandably, those are very similar TAS numbers that I see with my IO-500 Cirrus. APS taught me that 50 degrees ROP is the very worst (most harmful) power setting. It certainly does produce more power than 50 degrees LOP but at the expense of maximum engine stress (internal cylinder pressure). Coincidently, it's also the power setting that is most likely to lead to pre-ignition and detonation.
I don't have the APS PP presentation material you asked for (I presume it would be copyrighted anyway) but I do have a chart called the "red fin" that was derived from APS power setting recommendations/ data. It's included on a checklist card that I put together for my SR22. You're welcome to download it and modify it to meet your needs. As long as the intersection of FF and degrees LOP are outside the "red fin" I know I'm at a safe power setting:
On my IO-550 I have determined that a quick and safe "go to" FF setting for LOP operations are: 15.5 gph up to 4000 ft MSL; 14.5 gph from 4000 to 7000 msl and 13.5 gph at any altitude greater than 7000 msl. Set it and forget it until I'm leveled off in cruise and have time to fine tune it.