Hi Keith,
All else fails, and I mean all, try using a cut-off wheel or Dremel tool to slot the center of the knock-off to fit the blade of an impact driver.
Slotting the center, you avoid damaging the threads on your hubs and wheels. Just set the driver to the direction needed for the side you are working on, fit the heaviest flat blade driver tip into the slot you create and hit with a heavy hammer (aka BFH).
Ruins the knock-offs, but should loosen it up and allow you to remove with the original wrench without damaging the hubs or wheels. When you replace them, clean the threads and use some neva-sieze to prevent this from happening again.
BTW, as mentioned, the knock-offs tighten and loosen in different directions depnding in the side of the car they are on, which I'm sure you are aware of. However, the hubs will fit on the wrong sides. Very dangerous, as the wheels can loosen-up while driving. If someone put them on reversed and tightened them to the point they are siezed because they loosened so much, that might explain the issue. Probably not the case, but did you check that?
Hope that helps. Let us know what you find out.
Safety Fast!
Art