It may actually be helpful to emulation. There's a technique called High-Level Emulation, where instead of emulating the hardware registers that are twiddled by the SDK function, you recognize the call to the SDK function itself and emulate the whole function in one go. This can provide a massive speedup over low-level emulation, but relies on the game primarily using the SDK. This was also used to emulate the N64 on Windows 95.
It may actually be helpful to emulation. There's a technique called High-Level Emulation, where instead of emulating the hardware registers that are twiddled by the SDK function, you recognize the call to the SDK function itself and emulate the whole function in one go. This can provide a massive speedup over low-level emulation, but relies on the game primarily using the SDK. This was also used to emulate the N64 on Windows 95.