I really don't see this tech as being very useful outside of a few specific situations. You basically have to predict that your opponent will throw out a move, since v-cancelling's tight timing makes it almost impossible to do on reaction (Except maybe for a falcon punch or charged Smash attack). If you guess wrong, you'll either accidentally air dodge if you are in a neutral state, or lose the ability to tech if you're in a tumble state. Since it can't be done in hitstun, it won't work during combos, so it'll be even harder to predict whether your opponent will throw out a move. Not to mention the fact that your fingers aren't that good at multitasking, so you won't be able to get as many SDI inputs in or your DI might be slightly off as a result of a v-cancel attempt.
A use I do see for it is to survive a fully charged smash or a falcon punch as a Jigglypuff who missed a rest or any other character who's shield broke. These timings are possible (and comparatively not hard to learn). You can go by sound for the falcon punch, and every fully charged smash takes exactly 60 frames. But be careful because your opponent might not charge it fully as a mixup. If you aren't paying attention, you might airdodge offstage and die where you might have lived if he does this.
EDIT: People can potentially discover option selects utilizing this tech, which would be cool.
EDIT2: A puff couldn't even use this during a missed rest, she's grounded.