DoN's 3D-Pathfinding / Flying-AI system (with full source!)

I am trying to figure out if I need this. I need a flying AI that can chase a point in 3D space, this point will be moving, because it’s attached to the player, who is also flying. I don’t need any obstacle avoidance. I would like to use behavior tree.

I have this installed and it can move the AI, but I feel like I want to just have 1 gigantic voxel and disable obstacle avoidance/pathfinding. I only need to go straight and the maps are big (over 100km).

Should I just use waypoints?