This seem only a tag with the engine subversion for future use:
// Automatically tag the engine version in this shader so we can do some #if trickery later.
PluginShaderFileContents =
FString("#define NEOFUR_UE4_ENGINE_MINOR_VERSION ") +
FString::FromInt(ENGINE_MINOR_VERSION) +
FString("
") + PluginShaderFileContents;
Anyway no hurry,
for now it’s okay