There was a rumor going around that it was possible to B-Reverse during when a MArt de-activates, however I tried doing it on my own & couldn't do so (I really don't believe Shulk can B-Reverse the MArt de-activation, let alone Pivot / Turn-Around the direction at all; we have to mash the B button 2 - 3 times, so doing a B-Reverse or dare I say a WaveBounce input would be hell to attempt trying even if it does work). The first step would be to know if we can pivot aka turn-around our direction airborne during the de-activation or not. Then at least I can drift my aerial away or not depending on the air spacing.
EDIT: As a side note, I updated the OP with nicer cleaner diagram pictures of the U-tilt, D-tilt, & F-tilt that are more accurate in terms of the hit-boxes, check'em out.
And, I'm thinking on the secret topic with B-Sticking for Shulk would be kind of interesting, considering that would make approaching SH > N-air & SH > F-air absolutely safe. I'm now also curious about the sheer distance difference between a pivoted Back Slash & a WaveBounced Back Slash as well.