What do you mean “bake settings”? It’s only a tool for setting exposure in a photographer friendly way; ISO/Shutter/Aperture. To me the exposure setting is cryptic. Exposure 0, what does that even mean? You can also disable it after setting everything up, exposure will still be set to whatever value was determined.
Scientifically? No. Visually, yes. Preset the camera exposure to known values which will produce expected results, then replace sun&sky with hdri and adjust its strength until it produces similar results. Now you can use those interior lighting assets without tweaking all of them.
For lighting interior scenes, I much prefer sun & sky (only sky is preferred due to noise) over hdri.
You can’t derive a luxmap in cycles. Try Dialux or some high end architect software for that. You can only do reflected light using filmic false color. The problem using a white diffuse as a material override is that all emission surfaces will be overridden as well, and obviously all energy from specular bounces are lost.
Use filmic false color to help you set exposure, as that is what photography deals with. But luxmaps are out of reach, so you can’t do architectural lighting studies.