Folks…..here is a statement that is going to ruffle a few feathers, but after the dust settles you will find what we at APS say about this topic is correct, so please bare with me.
The Lean Find function is one of the worst understood and almost useless functions, along with the JPI CLD and DIFF functions.
The hysteresis in probes and the maths algorithms are just not up to the task, and there is a physics experiment going on while you use them.
The Lean find does help when determining the GAMI spread, but after that forget about using them. The reason being is if you use them as most people do, you will end up at a far greater (less efficient) LOP setting than you actually think you are at. If you don't believe me go try it.
Also most EMS are not well configured in the % power calculations. The Dynon is, the AuRacle is, and I am not confident about the rest. So onto the ROP and LOP indicators, if you are using a fixed pitch prop, the ROP/LOP function is useless, RPM and thus EGT fluctuations confuse the heck out of the EMS so it gets easily confused.
The best calculator is between your ears 
Ignore the ROP/LOP indicators.
So Don here is an extract from a recent post I made.
1. Line up, boost pump on, mixture rich and roll.
2. Climb at a sensible airspeed, not Vx or Vy, in the -10 that is 120KIAS through to TOC using a Target EGT method as described by APS.
3. Level out…..DO NOTHING….as John Deakin would say, an airline pilots favourite thing!
4. Once the plane has accelerated and the CHT's start falling close cowl flaps if fitted (yes I know RV's don't normally have them). then do nothing some more.
5. After a few minutes of doing nothing you will get fidgety, having dealt with ATC, checked your flight plan etc, now set the cruise up by setting say 2400/2436/2372/2490 RPM Yes whatever is a smooth setting for your plane, then do a Big Mixture Pull, and leave it there.
6. Once the CHT's have rolled off a fair bit sneak up to peak FROM THE LEAN SIDE, and find the first one to peak, then roll back leaner and set that to the appropriate amount LOP. Be that 10/25/40/60 or 80 LOP.
7. Another 10 minutes down range turn off the boost pump.
8. Continue the flight until just before TOD do a AMG check for 10-15 seconds on each mag (leave mixture alone) and only touch RPM (reduce to say 2000) on descent, and then throttle only to stay out of the yellow arc, until at the hanger door, shut down with mixture to ICO. Flight over.
Note that when you know which is your last to peak (from the rich side) richest cylinder, lets say it is number 3, you can just pull to a known fuel flow or better still do a BMP, then after everything has cooled off sneak up and watching the RAW DATA only for that cylinder, find peak. Then lean back to XdF Lop and be done with it.
You will be the correct amount LOP and not far more so, you will be at the best BSFC and not excessively leaner than you need to be and life will be good.
Don, let me address one other point,
After reaching my cruse altitude I set my power
What do you mean by this? I assume all you are doing is pulling RPM back to a smooth RPM level, anywhere from say 2300-2600 would be fine. You may find in the 2450-2550 range works well, you may find its a bit less. But please leave the throttle wide open.
You want most of the time to be operating LOP, so WOTLOPSOP is the idea.
If you really want to understand the whole combustion event, how engine monitors work and how best to understand what they are telling you (how to save money) and a lot of flight safety topics, get along to the APS class that John, Walter And George will be running in March.
Hope that helps.
