I think if you pulled it apart you would be amazed how much dust and dirt got sucked into the motor. Mine is pretty new and the lower bolts had tons of crap on them when I pulled them out.
With new filters there was no noticeable change in airflow. I measured temps of the motor with an infrared gun before and after and noticed no change.
I also did a half assed flow test with a piece of paper and there was no difference before and after.
Obviously this will change if the filters get clogged.
To each his own, certainly not saying it’s essential. In my case with the motor on the floor i thought it was worth doing.
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