Dark baked GI

Hi, been having issues with not enough GI in my light bakes.


The image above has the trees disabled. Here is enabled, more light should pass through even if these trees were completely solid.


Some areas under the trees become pitch black, and it seems to be because not enough GI bounces/samples.





Another example would be a small tunnel like this, which light should fill up no problem. However even a few meters of covered area and the light maps go almost completely black.



Setup:

Unity 2018.4 LTS, GPU lightmapper.
Auto exposure as a PP isn't possible.
Ambient light is pretty much white/bright as possible.
Samples are very high, bounces are max, AO is off, Albedo boost is at 10.

Maybe this is physically accurate, but it seems way off.
Does anyone know how can I reduce overall baked shadow strength, or have some base ambient light? I never want areas to be completely black, physically accurate or not I just want consistent shadow strength like realtime shadows.

 

bump

 

Not supported in 2018 LTS, we have to stay on this version for a plethora of other reasons. The interiors are also very dark, is it not possible to have a baseline ambient light anymore? Do you have to use pointlights or something, because this would really suck! I don't care for physical accuracy in most cases, I just want some baseline ambient lighting, similar to realtime lighting...

Is there another work around for this?