buffer your roll through with the cstick. it gets you out of most shield pressure. if they're persistent/overaggressive, then they'll probably try to nair you after you roll. you should have time to do a runaway bair to prevent that.
as its been found, if you have to, double jump before the waveland. it makes it significantly easier for the waveland. the only drawback is, if the fox sees this, you won't have your double jump if they run in and uair you. and then they'll combo you.
if you see the nair coming, it takes some purposeful getting used to, but its possible to get consistent. its usually better to try to err on the side of caution. too early, and you just have yourself in a shield pressure situation that you have to buffer the roll out of. but too late, and you end up getting nair waveshined usmash uair or something along those lines.
i only roll with the cstick and shield now. sometimes its funny, cuz it causes me to fsmash at oddly opportune times when i mess up.