Making a call to USceneCaptureComponentCube::UpdateContent() will cause the compile to fail with an unresolved symbol linking error. This is inconsistent with USceneCaptureComponent2D::UpdateContent() which does not cause compile errors due to being declared with "ENGINE_API"
Result:
Without Engine_API, attempting to call this function causes compile errors
Head over to the existing Questions & Answers thread and let us know what's up.