I'm going to try less translucency and see if it helps. I don't understand what less opacity does; I thought that the possibility of that setting was only 'yes' or 'no'.
The biggest problem is the hard, deep shadows, which I just can't lose. That's also why I set GI (mhaze) to 2. Possibly this is due to the density of the foliage, so that no light can pass through.