[quote=gregb;462]Is it possible to add Add Product Type Properties to Membership products?[/quote]

Absolutely. You first need to create a membership product type.

https://hotcakescommerce....ership-Product-Types

Once you do that, then you're creating a product like any other product, except you select the membership product type. Therefore, the same product attributes you're used to using with a standard product still apply.