I just wanted to let everybody know, I was able to install Mega Heathrow Xtended into P3DV4 by simply pointing the installer to my P3DV4 directory.  I had to manually add the scenery using the scenery library.  But once that was done, Heathrow Xtended works perfectly in P3DV4.  No OOMs, good night lighting.  There was a small increase in FPS over P3DV3.  Normal Autogen setting was enough to fully populate the surrounding areas.  

Do it on your own risk, Heathrow is not official supported for P3D V4. A official V4 Version will follow.

And maybe you find the parts, which will not work correct  sometimes, then don't ask for support fixes

Because we believe this topic has been answered we have closed it. If you have any more questions feel free to open a new topic.