As a Mario main, Snake's recovery gives a lot of height, but is slow and could be edgeguraded. During his up-b, Snake has super-armor, but a small part of his doesn't. If you want to edge guard him, aim for the upper part of his up-b. Mario back-air and neutral-air are fast and really good to throw out to aim. Even if you miss, you still do damage on him. Snake can cancel his up-b at any time, with any move, and can mash down-b for a short period of time to regain his recovery. If his recovery were to run out, or if he was to cancel it, back-airing him and providing constant pressure is definitely the way to go. Be wary of Snake and try to make the most of this off-stage moment, where he struggles.
Mario