Feel free to Set your version to Derivable. As per IMVU Creator Agreement when you mark a product as "derivable" in the catalog, you give permission to every other IMVU Creator to derive a new product from your product. This permission also allows those other IMVU Creators to set their derived products to be derivable. The original Creator who developed a product as part of the derivation chain are to receive payment of their share of the final catalog price in the derivation chain.