Thanks 
@das8track No the Megascans library is separate to the suite, it will be released as a standalone service!
Here is a quick and dirty scene I made today testing ONE instanced tree mesh with LODs- my aim was to get a nice overall grading and sense of space without focusing on the small details- close up trees are 30K tris, slightly further away are 9000 tris, and slightly further than that go down to 500 tris! Makes large forests running at decent frame rates very possible! Still much more testing to do on this front with a lot more variety in tree meshes and foliage, but it is a start Trees were created using GrowFX.
https://cdn0.artstation.com/p/assets/images/images/002/745/864/small/eoin-o-broin-04.jpg?1465238410