Where a MapEffectsLayer sits in the overlay stack: right above the effect it names. Every
overlay effect above it then works on it, and the ones at or below it don't.
Remarks
From the bottom, the overlay stack is bloom, grade, fog, edgeBlur, tint and vignette,
over the GPU chain. So after-edgeBlur puts a layer under the tint and the vignette, and
after-vignette over every effect.
Where a MapEffectsLayer sits in the overlay stack: right above the effect it names. Every overlay effect above it then works on it, and the ones at or below it don't.