If this is a proper place for a feature request:
It will be a nice option to use latest Vray's maps like VrayUVWRandomizer and VrayMultiSubTex in randomisation of uv coordinates and mixing textures per each forest item!
Also, the most widely used competitor "Multiscater" supports those two maps!
To me it sounds weird when a good instancing plugin does not support those maps from such widely used rendering system like Vray....