Adding a new Drone Entity?

[Hersh500]

Let's say I wanted to add a new drone that implemented some additional features, such as having a time delay to the propeller motor response or adding some aerodynamic forces such as drag. It seems like there are 2 options:

1. I would have to create a new DroneEntity subclass for the drone and a new subclass that inherits from RigidSolver that, when add_entity() gets called, adds my new drone entity instead of the original DroneEntity to the simulation. And then I would also have to override scene.add_entity somehow to make sure my new solver gets used.
2. I could handle all of the additional features outside of the DroneEntity class. So for adding a time delay to the propellers, I would manage that myself outside of the object by changing how I call set_propellels_rpm.

In either case, if I wanted to add some additional aerodynamic forces, I would have to do something like drone_entity.solver._func_apply_external_force(self, pos, force, link_idx, batch_idx). But, if my understanding of taichi is correct, I can't call that externally since it's a taichi function. And the only kernel method to apply an external force seems to be control_dofs_force in RigidSolver, which has additional side effects that might be undesirable, such as changing the control_mode of a dof (I don't fully understand what that does, though).

Adding new features in this way seems a bit messy. Any ideas or recommendations?