Dexta,
The only issue of running LOP without an EGT on each cylinder (and I suspect this is were most problems arise) is, that you have to get into a slightly different mindset with LOP and understand what your engine is doing. This is where the APS seminar helps. I really think a decent engine management understanding is essential before operating LOP.
If I remember back I think one of the first things that Walter said to me when I did his course years ago, that has really stuck with me ever since. Think of every Cyl as an individual engine, your trick is to get them all flying in perfect formation to become a single unit or engine. So unless all Cyl are producing roughly the same horsepower they wont be in formation. Well that may not be his exact words but that's the simple thought process that helped me understand what's in front or beside me and what I need to strive to achieve and I ask our pilots to think of an engine the same way as a series of engines that are connected by a common shaft.
When leaning to lean side of peak EGT you need to watch for the last cyl to peak, not your first as you would when running ROP and have always been taught. If you dont and you don't have a tight fuel spread or F/A ratio, then as you lean you may have some cyl's LOP (if you are watching for first EGT to peak and lean past peak EGT) but you may also have some at peak or 10-40 ROP and not lean or rich enough and in the danger zone. How can you do this with a single point EMS.
If you do this with a higher power setting then you can potentially have damage the like of what Yr right is seeing in his LOP operations disasters with cylinders showing detonation and burnt hot valves as that odd cylinder not flying in formation has crashed. So without an EMS in my mind, you really are really running blind. With a EMS you can pickup the start of light detonation and stop it before it causes any damage
I ask our pilots monitor our EDM's not only to lean but as part of their scan in flight as I feel individual CHT and EGT is very important in understanding what's happening in front of you and could well save your life by detecting an issue no matter if you run LOP or ROP, well before your other gauges react or you hear, feel a problem or see the oil on the windscreen.
If you invest in a EMS you will find after a while engine management will all make more sense.
I might ad we don't sell or prefer any after market EMS in fact we have three different brands and it all comes back to price and personal preference and how many bells and whistles you want.
For me I just require all CHT, all EGT, TIT for turbo's and Oil Temp. FF and HP is nice but I found that it easy to rely on FF and this could lead to a disaster.
For example we have had an issue in the past with K factor on FF being accidently changed and pilots relying so much on EMS figures that dips in our 210's pre and post were not getting done, laziness and thinking EMS figures looked more accurate than a mark on a stick. Inflight fuel calculations were not being done as they relied on the EMS, so the real consumption was different to the EMS figures pilot had used. CP picked it up on end of week review of fuel consumption figures for the particular aircraft and it wasn't an issue, it was however a warning to make sure with FF on a EMS you only used it as guide and get to know your EMS/aircraft and the importance of trending with all that beautiful data you have recorded. Get to understand your data.
Sorry to ramble on a bit. Thought I would try and give you a operators perspective after maybe 10,000 hours or more of EMS operations and LOP.