Corner plot of an alternative interior structure model illustrating the expected planetary properties under the assumption that the refractory element abundances of the planet match those of the host star. Therefore, only the stellar element abundances ([Fe/H], [Mg/H] and [Si/H]) were input as parameters, with [α/H] used as a proxy for [Mg/H] and [Si/H] due to very few lines used in the abundance measurements for those elements. No constraints were put on planetary mass and radius. The expected CMF for a rocky planet around TOI-4552 is 0.32, consistent with that of the Earth. This is just within the lower uncertainty bound predicted by the interior model constrained by the mass and radius measurements (CMF = 0.54$$; Section 5.1; Fig C.1).