Rotational properties of the sample. Top: Histogram of υ sin i values resulting from the iacob-broad analysis of the 285 O-type stars in our working sample, highlighting the diagnostic line considered for the analysis. Bottom: Comparison of the v sin i estimates resulting from the FT and GOF analysis strategies. The diagonal dotted lines indicate differences between both quantities of ±10 and ±20 km s⁻¹.