the mdma high is short enough orally, so i see little point in snorting it.
the only occasions where snorting is an option is either sharing a too small amount of mdma to get everyone high if dropped (a little more than half the oral dose is enough ime; still nowadays i'd rather wait roll at some point in the future rather than have a disappointing or very short roll) or for the last redose in an evening. if you show signs of coming down, the mdma in a swallowed another tablet might be absorbed too slowly for you to get the high back again, but snorting works reliably. also, with the shorter duration of snorting i get a sharper dropoff of effects after coming down, making the return from the party a little more clearheaded and pleasant.