Well Gentlemen,
I cleaned my pellet grill out entirely prior to running this last batch of 2.5x12 walton summer sausages. I also put it in the shade for the full cook and noticed it was running significantly cooler than usual. I ran it at 150 (therm showed closer to 135-140) for 4 hours (was afraid to raise temp initially and cause shriveling) and then 16 for another 3, and then 170 for the last hour as i needed to leave and i was suprised how slow they were cooking to a IT of 160. They came out looking perfect. I think not starting out with a cleaned up and fresh grill is to blame for the fatout. I had no flare ups but i think the sizzling grease on the tray and elsewhere may have elevated my temp, Perhaps combined with the direct sunlight.