Yes, adjusting the seating depth is something you do once you find an accurate load.

Its done more to reduce the jump the bullet has to make to engage the rifling, so that the bullet has a better chance of starting down the barrel with good alignment. When you get to the point of where you are adjusting in increments of +/- .010" you are just trying to squeeze the last 1/4" reduction in your group sizes. If youwant to use the engine analogy, adjusting seating depths before getting a good load is like setting your timing before installing a distributor.