Brightness under material editor is a good option to fine-tune the texture but it’s for the whole texture. It lacks the ability to over due textures…
Another option with a Contrast slider would let us get extrapolate more and have for example a more bumpy map (without changing the values) or more contrast on reflections. It really feels that would save a lot of work by avoiding going back and forth by doing it on photoshop or similar…
Cheers