const PARALLEL_EQ_THRESHOLD: usize = 8;Expand description
Minimum compiled-equation count before we hand the per-vertex loop to
rayon. Empirically: presets with ~3 cheap equations stay faster
sequential (warp-exec time is dominated by per-thread MilkContext
clone + work-stealing overhead at ~1 ms/frame baseline cost), while
presets with 10+ equations see a 2-3× wall-clock win on a 12-thread
box. Picked 8 as the breakpoint after measuring three reference
presets (3 / 26 / 35 equations) on the bench_render tool.