also in general, I find the pan flag a lot more aesthetically pleasing than the bi flag, and it is also more clearly inclusive
red + blue + yellow clearly indicates "any and all genders," whereas the bi's mixing of red and blue really doesn't.
also, the bi flag is really a five-striped flag, where the purple is ⅕ the flag. the pan flag puts the yellow equally among the red and blue
like I love people trying to quash out the exclusionism in the bi community. but, I'm pan.