So there was probably some weird stuff going on in the yards, both from combat experience and (in Fluckey's case) just plain old "hey, what if we do this?..." This is what makes boat research so interesting. I know Plunger's skipper commented that the squishing noise made by his wet wooden planks almost gave him away. As a result, Plunger's yard period was pretty much a master-class in how to build the perfect boat, with every Navy bureau looking at her with a fine tooth comb.
O'Kane's list of "why doesn't my boat do this" complaints was also read with a microscope. Sometimes, field mods would be done ahead of the proper gear. Case in point being rubber washers nailed everywhere to "sound mount" certain pieces of gear, pending the arrival of the new silenced equipment.