Installing a new vanity, and like idiots, we forgot to account for a floating cabinet when plumbing hookups went in, so the drain outlets have about 3-4 inches clearance below, but there’s plenty of space otherwise. The plan is actually to try some waterless valve traps anyway, but if we don’t like them, or there’s some future inspection issue, can it simply be sloped up at a 1/4 -1/2 in grade? Maybe also with some bends to save space?

My plumber comes to install in a few days, and I’d like to know how much of an idiot he’ll call me