Fractional contribution of disc-like (purple) and halo-like (orange) GMM components as a function of metallicity for high- and low-α stars. The scatter points show the location of the knots chosen to run our model. The bands are 1 σ uncertainties on the converged weights. These fractions are computed for a fixed Gaussian for halo and disc-like stars when the MCMC is converged. The converged azimuthal velocity and velocity dispersion is shown in the legend, shown in units of km s⁻¹. The low-α model clearly shows two separate populations (thin disc and accreted) shown by the step function that could be misclassified as a rapid spin-up, while the high-α model shows a shallower monotonically increasing(decreasing) profile for the disc(halo) with [M/H].