A veeeeeeeeeery long time!!! ((((
There are somewhere render farm for rendering such?
hahaha. If you need a render farm and more than 27 hours for a basic living room scene, that is a sure sign that you are going overkill. That’s why you’ll see a lot of people warn against touching the .ini’s, because you don’t actually know what you’re tweaking. So you’re running a whole lot of extra calculations for random settings. Maybe take it one setting at a time and document your results.
Also, it looks like your CPU might be aging a little? Lightmass is entirely CPU based and works great for CPUs with lots of cores.
new tests with scale .8, bounces 100, quality 10, smoothness .65 (11.5 hours to build)
Getting nice smooth shadows in my scene like under the stairs here and on the floor.
Awesome 
The problem with koola’s ini is that we stated himself that he tried these values are totally random…So i’m not sure it’s a good idea to blindly take theses values for any scene. Koola’s scene are also very small but in a big project his settings (ini) are not possible.