I have to wonder if you're using winelib in a way that's not appropriate.
Winelib is not a useful intermediate step in porting an existing application to Linux, as most of the work involved in porting to winelib will not help you with a native Linux port. At some point you have to make a clean break from Windows, and winelib doesn't change that. It just provides a way to delay that painful step, while doing little to reduce the pain when it comes.
Nor is there typically any advantage to running existing Windows code with winelib compared to running a Windows exe or dll in Wine. While it's true that winelib can be used to port Windows code to a new CPU architecture not targeted by MSVC, there's not much demand for this.
Most people who think they want to use winelib want to do one of those things and don't realize that winelib doesn't solve any of their problems. Almost no one has a real use case for building existing Windows code with winelib. Given that, improving winelib's Windows source compatibility doesn't make it much more useful, and it probably isn't worth anyone's time.
Winelib works best to support a limited amount of new code (a single .dll.so or .exe.so) that acts as a bridge between Linux and Windows code.