I'm trying to implement a new import entity to be made available through the ImportExport module (which is actually extended by Firegento_FastSimpleImport2, but that's not relevant for this question) for importing a collection of attributes (just the labels not the values) which will be used for product attributes, but might be needed to be extended in the future for customers or categories. I manged to do a new import entity and make it available through the import interface.
My question now is if there's a recommended way to use Magento's API for attributes (maybe from the EAV module) or I just make a pseudo entity and import directly in the attributes tables?
The module install / update scripts are a no-go for this because it needs to be further integrated and withing a larger system and work seamlessly via API or CLI commands, repeatedly.
I've seen only one example of programmatically adding attributes without install/upgrade scripts here but I don't know how I can reuse it in implementing the ImportExport module's AbstractEntity. Any pointers would be helpful.