Even if available Jax is unable to call a Tesseract's jacobian endpoint and always chooses to batch over jvp (jacfwd) or (vjp). As Tesseracts don't currently support batched tangents and unbatched primals (see issue in tesseract-core for more details on design options) Tesseract-JAX is forced to perform multiple sequential calls to the Tesseract which can be very slow and inefficient. Until we support batched tangent vectors in Tesseract-core there is nothing we can do here but noting this here for awareness.