glum
If you consider the slipstream to be a tube of fast moving air the diameter of the prop rotors that may be so. Sadly that energetic tube of air will induce flow at say 1.5 or more times the prop diam. Admittedly it will not be as fast as the core flow but it will still represent a huge downwash at the top of that fin and to take the longit control sting out of that you will have to align the tailplane LE up.
The reason helicopters with a small tailplane have to put that at a big LE up angle during transitions is similar (since that the tailplane is not actually under the rotor itself). Air is quite viscous and works to reduce any simple shear between high and low velocities.
BTW I believe that marked shear stresses produce a lot of the noise associated with jet engine exhaust. As a result nozzle design features try to encourage the mixing between the jet and the surrounding air to reduce shear related noise. Here you might like to increase the actual shear and so minimise the effective diam of the rotor's influence but I suspect nobody knows how to do that.