I know exactly how export forwards are implemented, but it's not a small change for Import Patcher to support them. IP is architectured to patch Imports, not Exports. "It's impossible. But doable."
Three types of dependencies are still not supported: import forwarders, export forwarders, and dynamic delay-loads. I've been learning a lot about export forwarders lately and if import forwarders work the same way, both of these should be relatively simple to implement.
KernelEx 4.52 runs as an MPR service, thus it loads after MPR. I assume this is why you're trying to patch MPR instead of using Kexstubs.
NTDLL.DLL interfaces directly to drivers and the OS, so it really is an impossible substitution. Kernel32.dll is also extremely OS-centric and off-limits for substitution. Also Kernel32.dll is non-relocatable, so two versions can't be loaded at the same time.
The best solution I see is to rebuild the Wine or ReactOS sources for MPR.dll and static link the necessary functions from the other librarys.