And the plugin linked here only works with the old render pipeline. The one with known bugs. So there's no way for me to directly use this. I would have to fix and port it first, to make it compatible with Unity's new pipeline.
And that beaviour of Unity stopping to support the working old stuff as soon as a new technology grabs their fancy has been going on for long enough that by now they're famous for it. Plus since they don't give source code access to the C++ part, you have no chance of fixing it yourself.