A day after adding them, I turned two things off by default.

The first was rendering weaker devices at 0.7 times resolution and rebuilding the detail over several frames. It is cheaper, and on paper it is a clear win. Then I put the same spot in La Sarraz side by side on a GTX 1050: house edges, branches and a parked car were smeared next to a crisp native frame. For a project whose whole point is that the place looks real, that is the wrong trade. It went back to opt-in.

The second was the shadow on the splats. On the same graphics card the Ludlow benchmark scored about 6,200 with it and about 11,500 without, and looking up the shadow four times instead of once made no difference, so softness was not the cost. Later that day, moving the lookup from every pixel to once per splat brought the cost down far enough that the shadow came back on by default. Cloudy places also got shadows along their own direction, not straight down.

The lesson I keep relearning: a number going up is a reason to look, not a result.