Are you thinning your Model Air? If so, ratio, and with water or Vallejo Thinning Medium? Apols if you showed it and I missed it. Airbrush brand and nozzle diam? (.3mm?) Pressure with Vallejo?? Love your geisha. Such a shame Hasegawa don't include a pilot figurine with their 1/48 kits. Fortunately, ModelKasten to the rescue. No Special Attack Unit decal options in this Ki-43 kit unfortunately otherwise I'd do a mini diorama with the school girl figurines traditional wave off farewell. Enjoyed the vid.
Sometimes I thin model air with airbrush thinner and I only add one or two drops. As for the airbrush I've been having issues lately so I've used everything from a Paasche Raptor to a Grex TG3.