A show flap will not do much to your exhaust gas temps. IMHO
If it did anything what did it do for your engine temp?
The Pro likes to get hot with low to no snow. Find more snow or get off the trail to get some fresh.
With the right snow flap circulating more snow into the coolers, this will increase coolant temperature causing engine temperatures to decrease, therefore causing lower EGT readings.
We have done the testing on these in the mountains in real world spring conditions, this is no speculation.