not sure if you saw this, about 8 months ago Bentley Systems is no longer going to work on vue or plant factory so its perpetual free with no support but they are still committing to security fixes.

https://www.bentley.com/software/e-o...free-downloads

All the assets including the textures and models are now free for commercial use, you don't have to incorporate it directly into the game engine because you can export trees and plants out of plant factory. I believe it even supports blender since i saw this on the blender artist forums.