In the upper (lower) panel, likelihood contours and distributions are shown for decreasing (growing) neutrino mass in the exponential potential case. For the plots on the diagonal, dotted (solid) lines are mean (marginalized) likelihoods of samples. Similarly, black lines on the plots exhibit 1- and 2σ contours of the marginalised probability distribution, while the colours refer to the mean likelihood degradation from the top (dark red) to lower values.