Mass-radius diagram for the poly-quark EOS (α = 1) with the curves colour-coded according to their Λ(M_1.4) values. The black-on-white solid line denotes the SLy4 EOS M(R). The regions with different Λ(M_1.4) overlap each other, also because one sequence may have several values of Λ(M_1.4) due to the nature of the strong phase transition around M = 1.4 M_⊙. The non-trivial behaviour of M(R) hinders the separation of the EOS on the M(R) plane with respect to the values of Λ(M_1.4) they yield (as proposed in Annala et al. 2018).