this is the response from rokas:
This is our new library. These presets are made with an idea of using multiple ForestPack objects (as layers) and with fine control of the look by adjusting each "layers" density.
First start with preset for base layer from presets with number 1
If area is large, use Yellow outlined preset with text Large.
If Your lawn is small, use Orange outlined preset with text Detail.
Then create new ForestPack object(-s) and add optional "Layers" from presets 2-7.
You can add one or more- depending what You want, what looks good for You.
Or You can use some predefined All In One (AIO) (outlined in thin green shape) presets with just one layer with less density control, but its nice and quick.
They are also prepared as Detail and Large for optimal performance.
All the possibilities in Your hands.