As a (non-current) AG pilot with, maybe, a couple of hundred thousand low level, low speed turns and twenty thousand low level base turns to land at minimum speed, in every conceivable up/cross/down wind combination, I am utterly positive that the whole 'parcel of air so no effect of wind' theory is absolute BS. Steady state equations prove nothing, it is a dynamic shear event and you can pontificate to your heart's content but it won't change reality.
I just deleted a long winded explanation as those unbelievers will never be convinced and will spout 'proof' long and loud, believe what you want, I have my own opinion, and supporting evidence, you are welcome to yours. Mine works for me.
HD