Gracias por todo. Si alguien supiera resolver el problema inicial, me seria muy útil, aunque por ahora utlizaré el método mencionado.

De nada, nos vemos.

Mira que dice sobre los colliders en la doc de Unity:

Collision Detection	Used to prevent fast moving objects from passing through other objects without detecting collisions.
- Discrete	Use Discreet collision detection against all other colliders in the scene. Other colliders will use Discreet collision detection when testing for collision against it. Used for normal collisions (This is the default value).
- Continuous	Use Discrete collision detection against dynamic colliders (with a rigidbody) and continuous collision detection against static MeshColliders (without a rigidbody). Rigidbodies set to Continuous Dynamic will use continuous collision detection when testing for collision against this rigidbody. Other rigidbodies will use Discreet Collision detection. Used for objects which the Continuous Dynamic detection needs to collide with. (This has a big impact on physics performance, leave it set to Discrete, if you don't have issues with collisions of fast objects)
- Continuous Dynamic	Use continuous collision detection against objects set to Continuous and Continuous Dynamic Collision. It will also use continuous collision detection against static MeshColliders (without a rigidbody). For all other colliders it uses discreet collision detection. Used for fast moving objects.