The simple answer is to just not breed the morphs that are prone to it.
I get the point you are making and I do not necessarily refute it but I offer up a few thoughts playing devil's advocate:
-While rodent breeders do not necessarily gut-load, most commercial rodent diets have been balanced to provide/meet the needs of the rodents so they are, in effect, being gut loaded.
-If nutrient-deficiencies in our animals were the cause of the bug-eyes then should we not be seeing bug-eyes occurring across the spectrum of our hatchlings and not only among very specific morph combinations?
-I fully agree with Dave that obesity should be avoided (in all snakes, not just balls) but again, if obesity were a contributing cause then should we not be seeing a much higher instance of defects across the board in our breeding because if we are being brutally honest most keepers do overfeed their animals?