I am working on a module that is essentially replacing a number of Magento features with custom logic. This is mainly due to the fact that I require pricing to 5 decimals of precision, but that is beside the point.
My module, for lack of a better term, is modelling "materials" and is a representation of the store owner's existing SKU/Catalog system.
I have several entities in my module, each representing a different segment of the catalog taxonomy. For example, a typical SKU will look like "AA-TTTT-SSSS-CCCC-ZZZZ", each of those segments ("AA", "TTTT", etc) are modeled as a different entity.
Up until now, I have been using a flat structure for each entity. As I start getting deeper into the build and finding more and more attributes I need to include, I am thinking it might be beneficial to move some of these entities to EAV, as there are no shortage of saved entities that have mostly empty fields.
At this point, my question is simple:
What are some concrete examples of real-world use cases for using custom EAV models in Magento? If you've chosen EAV for modelling a specific custom entity, what aspect of the business logic helped you to choose?
Of course, I am perfectly aware that there are plenty of articles describing the EAV system, it's pros, cons, etc; however, none of these articles really explain why you would opt for EAV specifically as it relates to Magento.