Including multiple versions of the EFM's API requires code duplication in the EFSPs system that can handle mapping the EFSPs classes to the generated classes the EFM expects. This is because multiple versions of the code base need to be operational at the same time for different EFMs. Generated code from the EFM can also be challenging when it is incomplete or incorrect. Manual modifications of the generated code is required for each EFM an EFSP integrates with.