Best Lighting Practices For Foliage and Landscape?

I have been getting great interior lighting results for ArchViz like projects, but am currently failing in achieving even decent lighting on landscapes with foliage.
Hopefully someone can point me into the right direction or help me out if you maybe already have experience.

I have a big landscape (8kmx8km), it has materials on it and is full textured etc.
With dynamic lighting my landscape and grass with the grass layer looks really great.
However rendering all that takes up a huge amount of my GPU, so ofcourse performance isn’t all great on my GTX1080.
So I tried baking my scene instead, which meant I had to switch from the Grass Layer to the Foliage Tool, since Grass Layer doesn’t support static meshes/lighting.

I have a small patch of foliage to test out the lighting on my 8x8km landscape.
However the results are not at all what I want when I bake on medium quality.

I tried increasing the Landscape Static Lighting Resolution from 1 to 3 and even 16, but it seems to stop at 2. Increasing it beyond 2 does not make the tiles smaller in the Lightmap Density Debug View.

Can someone help me out with how to setup foliage in combination with static lighting on big landscapes?
Because I am trying to make this to be a massive map for multiplayer with mostly only foliage as assets that fill up the map.

Here are some screenshots of my results when baking, and an image of how it looked like with dynamic lighting of which is the result i wish to replicate.

As you can see in the Density Lightmap View, the terrain resolution is pretty small.
This is why I think my shadows are very blotchy.

So my question regarding “best practices” is;
Is it smart to increase the Landscape Static Lightmap Resolution?
Should I bake the lighting for all of my foliage, or does dynamic lighting only provide crips and clean shadows?
Having leaf shaders that make the foliage look wavy/windy, will this badly affect the static lighting in any way?

I am very new to landscapes and foliage, so any help is appreciated!

Hi, I’ve been working on a baking scene lately, and if you think I’m doing ok, we can talk about it

I actually followed some tips from other threads where I posted, where people recommended me to not use baked lighting for foliage.
I managed to pump up the performance a lot by changing a lot of settings and playing around a bit.
https://forums.unrealengine.com/development-discussion/rendering/1819805-best-lighting-practices-for-foliage-and-landscape-help

Also see image attached for how it looks like now.