Playing a bit with some patches, I had a look to the multi light sampling branch and ported it to 2.8.
The scene from here with light BVH:
and without:
It takes longer to render, but has less noise (only behind the table, there is more noise). It also looks more realistic (to me at least). What do you think?
The updated diff is available on the course download page, so that you can play with it 