Looks like that diverter does make a difference after all ... 30degF cooler on average for 3&4 and 15degF cooler for 1, but 2 stays the same on average :shrug:
I think that 3&4 are getting more air now and 1 is getting less (but might have been getting too much in the beginning and the shroud may not have been able to get rid of the air around #1
Out for some more testing and more diverters !
Sandeep