I think you are really on to something there! One of my first questions to Weber was the fan. It finally took me posting the question on amazon to get an answer. I only saw the actual fan for the first time in assembly video that someone posted on here yesterday. Once I get mine in assembled and seasoned I will repeat the same temp experiments.
One thing I really want to see is the temperature variance over a long period of time on each probe with my Fireboard extreme as the grill continuously goes through its cycles of moving the pellets to the pot and igniting them over time. I know there are several ways to work out a 25 degree difference on any grill through a few home brewed hacks but the flames dancing around have me concerned more than a 25 degree difference across 2 or 3 feet because I speculate as the grill cycles through the pellets that the temperature swings will probably be a little higher and lower during those cycles.
Once I get a baseline and if I am not happy with it I will take a peak at the blower. It looks to be a DC Muffin type fan from the one video I saw. Im not going to re engineer my grill but if I can adjust alignment or something I will. If not I will figure out another temporary solution that works through as much of the temperature range as possible and try not to inhibit the searing ability or the free flow for smoke as much as possible.
To be honest, I have owned A LOT of grills and I am really OCD about even cooking temps. It is one of the biggest reasons I have tried so many different grills. I have owned almost every decent Weber Gasser, have had every kettle ever made except the sexy new summit, PK's, BGE, WSM and Offsets of several types. The only ones that were almost perfect without much fuss was the BGE, My Weber Smokey Mountain and an ancient original New Braunfel's smoker.
My Summit is now the most perfect of all of them but it required a bunch of modifications and I even have a spread sheet and notches on the knobs for the burner temps LOL. What I am trying to say is almost no grill is perfect and definitely only a few have perfect heat distribution. Ive cooked some amazing meat on even the worst of grills I didn't mention albeit with a lot more sweat equity but it all worked out. Long story short, if Weber don't fix it.....I will.....someway or another. I have wanted a good pellet smoker for awhile. I like everything the are supposed to be about. I think our Smokefires are the closest to actually really getting there. I still think its gonna be ride with some bumps along the way but between weber, 3rd party vendors and an awesome community like this......we will all figure it out so I will be keeping mine