Coefficients of the fitted models for flares in young M dwarfs. The values of ${\widehat{X}}_1$ and ${\widehat{X}}_2$ are plotted on the y- and x-axes, respectively. Each point represents an individual flare event and is colour-coded by the flare energy released in the TESS (left) or the FUV bandpass (right). Model fitting was performed using multiple setups: H6 and H6CIII for the TESS data, and COScut1 and COScut2 for the HST-COS data. Linear regressions fitted to the flare events for each star are shown as dashed coloured lines. To guide the eye, in the panels, the H6, H6CIII, COScut1 and COScut2 ratios are shown as dotted red, dotted black, dash-dotted grey, and dotted grey lines, respectively.