How to parametrize ISaveGameSystem::SaveGame() to use system UI

I’m trying to do an extension of a save system that supports standard save, quick save and auto-save. While the three operations are the same, quick save and auto-save do differ in one thing: Showing or not platform UI.

When using ISaveGameSystem::SaveGame() one parameter is bAttemptToUseUI, which raises system’s UI (in case of console dev, for instance, you’ll get native system UI). My Save/Load class calls UGameplayStatics::SaveGameToSlot() which calls said ISaveGameSystem::SaveGame() function, but bAttemptToUseUI will be hardcoded in GameplayStatics.cpp, and when I modify UGameplayStatics.h to have a static bool field to set as needed, compilation will fail because of the save system having an unresolved reference to -let’s say- UGameplayStatics::useSaveSystemUI, which I previously defined in the header. So how can I achieve this? My ultimate goal is to leave any save procedure to the same code, so I can get the behavior set via parameters.

Thanks in advance.