@major-mayer, you can certainly add punctual lights like point, spot, or directional to your scene with IBL. For example, if you need to cast shadows, you will need a punctual light to cast them as we can’t cast from IBL.
For your purposes, I would probably use a metallic of 0.0, as you don’t want environment reflections interfering with understanding the model. For roughness, I would try values between 0.4 and 0.6. The lower values will have sharper specular highlights which can help describe the surface as they roll over it.
Broader specular reflections can make subtle surface perturbation a little hard to discern. So I would err toward a little sharper specularity.