  We study multiterminal Majorana and conventional superconducting islands in
the vicinity of the charge degeneracy point using bosonization and numerical
renormalization group. Both models map to the multichannel charge Kondo
problem, but for noninteracting normal leads they flow to different non-Fermi
liquid fixed points at low temperatures. We compare and contrast both cases by
numerically obtaining the full crossover to the low temperature regime and
predict distinctive transport signatures. We attribute the differences between
both types of islands to a crucial distinction of charge-$2e$ and charge-$e$
transfer in the conventional and topological case, respectively. In the
conventional case, our results establish s-wave islands as a new platform to
study the intermediate multichannel Kondo fixed point. In the topological setup
the crossover temperature to non-Fermi liquid behavior is relatively high as it
is proportional to level broadening and the transport results are not sensitive
to channel coupling anisotropy, moving away from the charge degeneracy point or
including a small Majorana hybridization, which makes our proposal
experimentally feasible.
