Doug, I know it’s been a long time since you put that Atlanta together, but Erick is correct.
You need to glue down the sheeting with the factory cores where they were relieved for pipe clearance. I would of not used the word “distort” though. Forgetting or omitting this step will cause you possible clearance issues (Pipe to belly pan) and even wing failures.
More clearance then what was done by the factory is needed for some pipes other than Hatori’s to fit the belly pan,
with some pipes you’ll have to clearance the center section further before glassing and installing the pipe/side plate to have the Belly Pan fit.
Keep it coming Erik!