At 5 o´clock you have always the hotest point in every turbine, ( if it works correctly with no hot spots), mainly in the startup. This is due to gravity effect, and swirl of the gasses. This is the best point to know the highest turbine temperature and this is why Wren recomends to put the egt probe in this point. If you put the probe at 5 o´clock in a Jetjoe, probably you will never start it due to overheating....... take a look at "5 o´clock" on the startup.

Regards.
Félix