I also usually run my smoker in the 225 to 285 degree range, but do bump it up to 350 for final few minutes of prime rib or similar, and occasionally do 300 - 325 for chicken finishing & meatloaf hurry-up & get done. I have had some carbon/creosote flakes on walls & door but mostly on the top/roof surface. To solve that issue I wipe down interior surfaces with paper towels dipped in warm water and then dry with paper towels. It's not a deep clean - just get rid of the loose stuff. I don't do it after every smoke, but do it more than "just rarely".
Don't know why my smoker builds up those flakes sometimes and not other times. Could be the heating/cooling of unit between smokes, or how much moisture was in smoker as it cooled down, or maybe it has to do with how clean it's burning (how often it cycles thru low/high speed fan and pellet dumps) while maintaining desired temperature, or maybe due to humidity inside the smoker due to outside air humidity drawn in by fan, or from size/type of meat load within. Don't really know. My FEC100 is about 5 years old now and have experienced that (minor) flaking condition only for the last 1-1/2 year or so. Don't know if you have any type of exhaust chimney on your FEC or not, but if you do that needs to be cleaned of excess creosote every once in a while to maintain airflow. (Similar to wood stove & chimney maintenance).
It's not much of an issue for me. Just part of the normal maintenance like changing the foil and cleaning the grilles the food sits on.
