This is an interesting example. It's a technology that's very important for staying alive, but not one that you'd expect to contribute to any kind of progress. It's just something you have to do to corn before eating it.
1: For anyone whose Nahuatl is a bit rusty: the English word for nixtmalized corn is “hominy”.
You don't actually need to nixtamalize maize. It's totally edible without and most americans today don't eat nixtamalized corn outside masa. It's just a process to make it more nutritious and importantly, nearly nutritionally complete. For ancient societies, nixtamalizing had a role similar to things like vaccination do for us today. It reduced malnutrition and the economic/social/political effects of disease. The difference I'm trying to highlight is that it probably wasn't understood as such and intentionally done for that purpose. Nixtamalization was culturally encoded as just what you did. Had they had a better understanding of nutrition, they probably would have made more intentional efforts to include the missing vitamins nixtamalization doesn't provide. We often see signs of those missing nutrients in precolumbian skeletons.
This extends to a surprisingly wide variety of ancient technology. Most metallurgy probably wasn't understood in the technical sense we think of it today until quite late. We see that with early glass, where people simply didn't understand what they were doing. Ingredients from specific areas would have specific effects, but sometimes didn't for reasons no one at the time understood. Craft communities would standardize on very specific, ritualized processes that simply couldn't be changed because they didn't have a good mechanistic understanding of the variables involved. One of the downstream effects of this is that poaching craftspeople is a viable strategy (they had the specific "recipe") and also that resources like sand from specific areas in syria and egypt were effectively non-fungible for centuries. You had to trade with whoever controlled that area even if you had the craftspeople.
By implication, this was something that had never been done before.
I'm guessing they had traditional assaying techniques, just with less accuracy than a contemporary chemist.
Andrew Carnegie discovered that certain "bad" ore was that way because its iron content was much higher than usual. Secure in the knowledge that this ore was actually better than "good" ore, he developed the techniques to use it.
Researching those reasons requires a lot of work and most people just want to get to the result step without necessarily understanding why you put the oil in the pan before the egg. They're hungry.