Reading through the documents I see that Multiverse has implemented SpeedTree. While this is a good thing, SpeedTree is quite expensive for the Hobby level and for the low budget Indi house. SpeedTree for games (The license to use the API) runs around $9000 per title, or alternatively you can opt for a yearly Sub at around $1000/yr.
So the question is, since the engine already is coded to use a 3rd party Tree system how difficult would it be to add more options? For instance there is
Woody3D http://woody3d.com/home/. Its not quite as powerful or all encompassing as SpeedTree but a license is only ~$195 and includes the API and Tree editor. And you only have to pay the additional license fee of $5000 if your title grosses over 250k.