How to use viewmode unlit in a shipping build?

[Kulagin]

Nice, there’s also easier solution:

@Kulagin

Here’s the solution that actually works:
In your C++ blueprint function library(create one if you don’t already have one):
Header:

UFUNCTION(BlueprintCallable)
static void SetViewMode(EViewModeIndex ViewMode);

Source file:

void UMyBlueprintFunctionLibrary::SetViewMode(EViewModeIndex ViewMode) {
	ApplyViewMode(ViewMode, true, GEngine->GameViewport->EngineShowFlags);
}