Drogoz's tail and horns are included in his hitbox so if he's far away, aim a just little higher than normal. This will prove helpful since you can shoot him once while he's not looking, and if he decides to ascend, you'll be able to catch him.
Kinessa's hitscan sniper rifle leaves Drogoz with little escape, where he is in the air or not. 2 well aimed shots can easily kill Drogoz. If Drogoz tries to bombard her with rockets, she can teleport away with Transporter.
When Drogoz is airborne, try snapping almost directly in an upward direction then snapping to his location horizontally. I do this when playing and seem to easily headshot him mid-air on a regular basis. example: https://youtu.be/DGVWJDimNv4?t=83