I noticed that the behaviour of this setting is exactly the other way around than its description:
Don’t Add resources folder to App Extension
If I enable this (= the box is ticked), I would expect that the Resources are not copied. However, it is exactly the other way around.
Also, the implementation in the Projucer exporter (that I suggested myself a few months ago) is not very clear as it’s using a lot of logic invertions and double negations up to a point that you could as well just roll a dice to figure out what it’s doing
// Wow, very !logic, much brain auto skipAUv3 = (target->type == XcodeTarget::AudioUnitv3PlugIn && ! shouldDuplicateResourcesFolderForAppExtension()); if (! projectType.isStaticLibrary() && target->type != XcodeTarget::SharedCodeTarget && ! skipAUv3) target->addBuildPhase ("PBXResourcesBuildPhase", resourceIDs);
So I’d suggest to just change the name (and the tooltip) to indicate the opposite behaviour.