If you or your student have hypermobile joints it is not recommended to stretch those areas. If someone can do a perfect Roll Up their lumbar spine can flex plenty already, so there is no benefit in practicing more and more lumbar flexion exercises.
If you or your student can do a split, there is no need to practice the Leg Stretches on the Ladder Barrel. You (or your student) will probably not feel much to begin with and then you might be tempted to find more advanced versions of those exercises. But this would make the already hypermobile area even more mobile. Creating more imbalance. Doesn’t make sense, right?
Instead, choose the opposite. If your lumbar spine is flexible, challenge it with flat back stabilization exercises, such as Short Box: Flat Back on the Ladder Barrel or Reformer.
If your hips are very flexible, challenge them with strength exercises, such as Side Lunges on the Chair or Side Splits, or Scooter on the Reformer, or Hip Opener or Hip Extension on the Trapeze Table.