When I assembed my JG 100 some years ago, I found the hottest place at idle was at the 4 O`clock position. But at full throttle, it was at 8. I thought this was because the higher case pressure, meaning the higher pressure straightened up the exhaust stream.
My experience is limited in this topic, so add plenty of room for my explanation.
Anyhow, I placed the probe at the 8 O`clock position, because 80% of the fuel is burned between half and full throttle. This worked fine for me, but my engine is not critical in temps at all.
I could be wrong again, but I think a turboprop has a hotter run, because of the resistance the exhaust meets to turn the drive and prop..?

Regards

Gudmund