Well, sometimes it's hard to judge whether a work counts as Moderate or Lots, as it's not always about number of pages as much as it is content and % of sex. Sometimes I'll upload a release and see what other people think it deserves.
And honestly, if a sex scene is like 1-2 pages, it usually doesn't get tagged at all.
When I see the tags, before I read something, I assume they mean: nsfw for nudity is in this manga, lots of sex for this manga is meant to be consumed as pornographic, and moderate amounts for some meaningful amount of story is in this piece but there's gonna be a significant amount of sexytime too.
This holds up in every case I can think of. I normally just attribute these tags for how the reader is supposed to read the manga.