I've brewed beer for many years. The malting process as you mentioned, does break things down, though I think its primarily starches (the endosperm's energy supply storage) into sugars useable by the barley seedling. It's essential to kill it, (kilning) to interrupt the sprouting process. This might be akin to the patio drying taking place in cacao processing. In barley production, its done in gas rotary kilns. Malting and kilning does have dramatic impact on the barley's flavor profile, it's diastatic power (the sugar-to-alcohol conversation) and ultimately the beer's flavor.
I know nothing about cacao, though I'm absorbing info like a sponge... But your intuition is probably spot-on, as Aussie's might say. Experiments were probably done by big chocolate co's over the past century, though those may be trade secrets. As the folks at Xoco point out, the drying/fermenting process by small farmers nowadays is probably hit or miss.
I'd do a controlled experiment at your in-laws house. Take a pod or two and wrap them in damp newspaper or muslin, take some other pods and remove the seeds, then wrap the seeds in damp paper, etc, with a control group with no fermenting at all. Dry each batch under the same dessicating conditions and then roast, grind and process. Do a taste test, varying ferment times and temp.
Would be cool to try this at home, but alas no cacao in Atlanta, GA usa.
BOb