thanks
Thanks all for the input.
I did come across John Deakin's column in avweb and that's what got me confused because he focusses on operation lean of peak EGT and that didn't match what I found elsewhere. Frankly it made me afraid of leaning anything in case I found myself operating within the "red box" around peak EGT.
But that's all clear now (i.e. a case of RTFM or more to the point, RTFPOH)
Mak