The Area Type property of an Area is stored as an element that has no identifying properties. No name and no category. They can only be found by using GetDependentElements on an area scheme.
The request is to make these more identifiable through name, parameter, and/or category.
A workaround that uses transactions can be found in this API Forum post: https://forums.autodesk.com/t5/revit-api-forum/set-area-type-property-of-area-element/td-p/10946478
While this does work, its not the most elegant solution that we could have.