On a surface that may be suspect to not being perfectly smooth, I use Ultra Grey, GM RTV, Mopar RTV. If the component needs to removed the other side of that junction would be dry. Gluing the gasket to a flat surface with Permetex, weatherstrip adhesive, etc works well to hold the gasket in place during assembly. This would be like oil pan rails, intake face, font of the block for timing cover or water pump. Metal to metal like a motor plate Ultra grey only, no gasket at all.
Doug