Hm, does the contrib plugins generate pch files? I think they shouldn't.
They all use the SDK.h pch; I believe they look in the wrong place if the setting is not the same.
Note: I have not confirm that this is true.
After testing, some of the plugins seem to ignore the correct PCH copy of sdk.h and instead used an old pch copy version of sdk.h.
So, my possible cause is NOT valid.In other words, you are correct the option has no effect on where the PCH file is looked to be found.
Note: That means PCH is not really being used by most
contrib plugins.
Tim S.