Wall-wash lights need more than the right fixture

For a new build, how do you decide where recessed wall-wash fixtures should sit and how far apart they should be? Fixed downlights seem simpler, but I’m not sure they’ll spread light evenly across a wall or avoid bright pools between fixtures.

The answer probably depends on what the wall is for: artwork may need focused, adjustable light, while a textured finish could look better with light grazing across it. But aimable fixtures aren’t automatically glare-free, especially when viewed from a sofa or across the room. How do beam angle, setback from the wall, and aiming affect that in practice?

Before ceiling plans are finalized, what would you ask the lighting designer to show or mock up so the light pattern and likely glare can be judged from normal viewing positions?