debugDisablePhysicalShapeLayers top-level property
Setting to true will cause all physical modeling effects from the layer tree, such as shadows from elevations, to be ignored.
Can be used to check whether excessive use of physical models is affecting performance.
This will not reduce the number of Layer objects created; the compositing strategy is unaffected. It merely causes the physical shape layers to be skipped when building the scene.
Implementation
bool debugDisablePhysicalShapeLayers = false;