The knowledge gained from understanding the chemistry and physics of piston engines is not only for the balanced injector multi probe fraternity it is a huge benefit to any pilot regardless if you never fly a machine equipped to operate LOP.
Here is the why.
A few years back I was in a position (briefly) to oversee a mixed bag of pilots flying piston SEA. One of these pilots was good enough to point out to me that he was unable successfully lean the IO-520 C210 as he had in the past (the company was a 50 ROP operation).
I jumped in and went for a ride, the single EGT and CHT was all it had, after take off and leveled it quickly became apparent that full rich equaled 75 ROP.
Somewhat concerning and leading to the next question where the hell was it during full power, fuel flow looked fine and it leaned smooth enough for a standard set up in cruise, so likely no blocked injector. With the engine as cool as I could get it a brief full power setup and very quick lean to have a look.
Just as I hoped I wouldn't see but did, at full power it was running 75 ROP too.
Back at the engineer facility I pointed out FF seems right but this EGT indication is worrying (note Fuel Flow is a pressure indication not fuel flow).
They changed out the probe, still no joy, they checked the FCU and all in speck and checked all the injectors too. At this point they were happy to shrug their shoulders happy to see it fly away. After I showed some persistence they did set FF's at the max permissible and this resulted in a positive change, now it was 85 ROP at full power and full rich.
I was still not happy, clearly this engine was talking its just that we weren't listening properly.
The engineering company brought in the big guns, a major aircraft and engine rebuild shop, they were keen to play down the significance of an EGT reading if everything else checked out.
Feeling very unsupported I decided to give TCM tech support in the US a call. I now felt supported they backed me up stating at the absolute minimum 150 ROP should be achievable and if we aint see'n it then keep looking and don't worry about setting a FF above red line.
The company in turn brought in a very wise local CAR 35 fellow hoping he would douse the fire and cure me of my troublesome thoughts, then I could release the aircraft back to service. Fortunately he was a well read and wise fellow and stood by what TCM and I had been saying, there is a problem.
In the end they set a smidge over red line fuel flow, they could not get past the fact the red line was a legal limit that could get them in the poo for willfully ignoring.
In the end I think I saw 125 ROP at take off power, far from ideal, but the best I could push for.
Without the knowledge gained through JD and et al that poor old engine would have been climbed out under power, often in stinking hot OAT's running just a tad outside of the optimum detonation mixture setting. And given the natural spread of inter-cylinder mixture maldistribution no doubt some cylinders were smack bang at best detonation.
Sadly not many seemed to care.