its not strict, and it does not require hours to do at all. If this link in particular is "impossible" for u, don't play mu, because it's a rather important link for her.
pads are inherently better for repeated direction inputs like 66, a stick won't help u do this better, practicing timing will. And you are definitely doing it wrong if you are waiting for her to land before u start to input it, u should be pressing the 2nd 6 by the time she actually touches the ground.
It does require a bit of timing, but the time u spent posting all this u could have spent in training mode modifying your timing until u can get it. Most people who complain about links like these just go in training and try it once and just repeat the same over and over and over without actually bothering to alter their timing, just hoping that they'll get it right at some point.
It will make it easier timing-wise, but the input is still the same, and u will still have to time the dash to come out right after u land. Instead of hoping ASW fixes your execution problems, do it urself.
Seriously, it's not even that strict, considering both other FGs and BB itself, there's stricter stuff. If u definitely want to learn this link, then don't complain and practice it, actually alter your timing depending on how it's coming out now.