Comparison of our Euclid forecasts for the WL-only probe with current bounds from KiDS. In this particular case, we switch to the same top-hat prior on ${log}_{10}{f}_{\mathrm{wdm}}^{\mathrm{ini}}$ and ${log}_{10}(m_{\mathrm{wdm}}^{\mathrm{thermal}}/\mathrm{eV})$ as in the KiDS analysis of Hervas-Peters et al. (2024). In the pessimistic case, we also adopt the same baryonic feedback recipe as Hervas-Peters et al. (2024) with a marginalisation over three baryonic feedback parameters (instead of six in our baseline treatment).