>>>Do all EGTs have to be LOPP, or is it when just the leanest one goes?  And, how lean constitutes enough to be considered LOP?<<<

According to GAMI at lower power settings (65%) you could get away with 50F° LoP.  At higher settings a larger margin is required: I use 100F° and at times I have powered back to 150F° LoP.  The Lightspeed EI allows for smooth performance even that lean.

Yes all cylinders must be LoP.  The horror stories that GAMI likes to tell are based on engines with single point EGT monitors that have some non-measured cylinders peaking at different times.

Robert M. Simon

ES-P N301ES