Right now, I am planning to mostly be

[serene karma]

There's no simple way to do that, and probably no way that's going to work practically

Whether you use the existing light baking system or make your own for some reason, the result will have to have all the limitations of texture mapping
Mainly the low pixel resolution

Toon shading can create perfectly smooth/sharp light ramps, but for textures they're impossible

[flat junco]

Alright, thanks for the input!

[flat junco]

Would the low resolution be as big of a concern in a case where a pixelization shader is applied to the game? That is a stylistic choice my team is considering.

The lightmaps don't necessarily have to be completely sharp, just "toon" enough, especially if there's a way to use point sampling with the lightmaps. Rough pixel edges may add to that aesthetic.

[serene karma]

Pixelization may help conceal artefacts, yes

I recommend you make a shader in Shader Graph that samples the lightmap texture and applies a toon ramp / step function / posterization to it and see how it looks

Might be bad, might not be

Lightmaps can be pixelated in the shader, or by directly modifying the texture import settings of the generated lightmap texture to enable point filtering

It can give an interesting effect

[flat junco]

the main issue i ran into when posterizing lighting involving multiple sources of different colors is that the rgb components are posterized separately, which is why i pushed most of the calculations into hlsl