  Motivated by recent experiments on low-carrier-density superconductors,
including twisted multilayer graphene, we study signatures of the BCS to BEC
evolution in Andreev reflection spectroscopy. We establish that in a standard
quantum point contact geometry, Andreev reflection in a BEC superconductor is
unable to mediate a zero-bias conductance beyond $e^2/h$ per lead channel. This
bound is shown to result from a duality that links the sub-gap conductance of
BCS and BEC superconductors. We then demonstrate that sharp signatures of BEC
superconductivity, including perfect Andreev reflection, can be recovered by
tunneling through a suitably designed potential well. We propose various
tunneling spectroscopy setups to experimentally probe this recovery.
