I've had Boat chips as long as there have been boat chips. They are stored 8-9 racks high (limited by shelf space) in tight-fitting Paulson or Chipco racks. It is a connected room, but there is no AC vent to the room, and the door is usually closed, so the room temp is in the low 70s to low 80s through hot Tennessee summer. They hit the felt maybe once a year, so the same pressure points do not change most of the year.
I cannot claim that others did not have flat-spotting issues; it just has not been my experience. I'm not putting them in "ideal" conditions, but there could be worse. I could see if chips were stored in loose or incomplete racks that there would be more psi on certain points, that may cause some deformation.
That said, if you can get away with just five-high, more power to ya. Some of us do not have that kind of horizontal storage space.
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