Mass-radius diagram for well-characterised sub-Neptunes around M dwarfs. Data were taken from the PlanetS catalogue (Parc et al. 2024), including also more recently characterised planets from the NASA Exoplanet Archive (as of July 17, 2025), that have radii and masses measured with a precision better than 8% and 25%, respectively. Planets flagged as showing TTVs are removed from sample. The two planets characterised in this work are highlighted with purple and golden diamonds, and the additional planets of the THIRSTEE sample are reported with pink stars. The coloured lines represent different theoretical compositions: the Earth-like composition (solid green line) from (Zeng et al. 2019); Earth-like cores with H/He envelopes at F = 10 F_⊕ stellar flux (dotted dark blue line) from Lopez & Fortney (2014); a model including water dissolution in both core and mantle (dotted grey line) from Luo et al. (2024).