Baffle step should be measured and not estimated. The theories used to calculate baffle step don't accurately reflect what occurs in a real placement.
Baffle step is function of boundaries with the baffle only one of them. If the woofer is near the floor or ceiling or if the speaker is near a wall you will likely need far less. The only way to get it right is to measure. Where will the speakers be placed relative to boundaries?
As far as whether the room correction in an AVR will adequately compensate for this, I can't say for sure. In theory, it should compensate but my experience with Audyssey says the results can vary greatly. Are you designing a passive crossover or active DSP?