I get a feeling you missed the part where it says "Please DO NOT attempt to use this plugin as a substitute for an actual dedicated 3D engine." as you appear to be quite ambitious with your project.
There is no LOD support in Baby 3D and if you're aiming to make a bigger open world style game you definitely shouldn't use this plugin.
Surely there are things you can do like instancing and implement a system that hides (makes invisible) parts of the world that currently cannot be seen. I'm talking event work here not direct plugin features.
In any case please do not be overambitious right out of the gate when the plugin hasn't even reached 1.0 yet.
