I have some usability suggestions related to lights.
It would be nice if you could add a more visible warning next to the shadow map filter radius slider, pointing out that the slider only works in open gl.
Furthermore, the directional light shadows can't be softened in raytracing, it would be nice if there was an option to make the "scale" of the directional light bigger and thus its shadows softer in raytracing too, maybe this "scaling factor" might be linked to the shadow map filter radius that works only in open gl.