A simple editor script that places an emissive object at the place of every light in the scene to emulate specular highlights on reflection probes when baking them.

Specular Probes Enabled

Specular Probes Disabled

Specular Probes Enabled

Specular Probes Disabled

The unity standard shader does not have a specular highlight term when baking lightmaps (even with directional lightmaps, but it only shades the diffuse term). As a result when a light source is baked fully within unity, you lose out on the specular highlight term you would normally get from realtime/mixed lights (unless you are using the shader that computes a specular highlight using the directional term from the lightmap). For PBR rendering, having a good specular term is critical for getting good and correct shading results.

This is a script that attempts to alleviate that by spawning an emissive object (that matches the shape of the light source) before reflection probes are baked in an attempt to emulate the specular lobe of the light. All of this at no extra performance cost at all! (because it's being baked directly into the reflection probes).

I was inspired by Zulubo's implementation, however I opted for my own and went for a more simplified but global solution that also can do area lights as well.