I would rather wait for them to reach the ground and conter with ground normals, which are airunblockable. Keep in mind if they airdashed, doublejumped or both before, so you can predict their behaviour after the airtech.
Or, if you play a zoning character like Nero, Hisui or Kohaku, set Traps etc.
But that's only me. I have no idea about the frame timing and if, you have to be VERY precise to punish an airtech with an airthrow. Too early, no throw. Too late, then it's you who gets punished.