A thinner revised version of the rear access port has printed significantly faster the original version and without much warping. Due to printing in a different plastic however, this print ended up too small to friction fit onto the enclosure again.

Rather than adjust the model and print again, I made a few notches on the hidden inside lip by softening in places with a lighter and deforming with the handle of a teaspoon. This worked perfectly, so I printed a second and made the same modification. Hopefully this will be a little more durable than an unmodified print, since the plastic has fused across layers in the places that are stressed when snapping the cover on.