Panels a and b: w80 velocity-velocity diagram for [O III] vs. Hα (a), and [O III] vs. Na ID (b). Each nucleus is identified with a distinct colour (see labels in Fig. 6). Dashed lines display the 1:1 relation. Panel c: distributions of η = w80/(2.355 × σ_*) for the three kinematic tracers, as labelled in the legend; the dashed vertical line marks the position η = 1.4 (see text). Panel d: [O III] (stars), Hα (diamonds), and Na ID (circles) η measurements as a function of σ_*. None of the velocity dispersions and w80 measurements are corrected for instrumental broadening; this correction would affect the only two σ_* measurements close to the MUSE spectral resolution (∼50 km s⁻¹), associated with the 20100−4156 N and F22491−1808 W nuclei, further increasing their η values. Panel e: [O III] (stars), Hα (diamonds), and Na ID (circles) η measurements as a function of the IC. The dashed horizontal line in panels d and e marks the position η = 1.4.