The 750–3,000 km markers band now draws up to 20,000 detections instead
of 2,500. At the 2,400 km end of the cross-fade the padded view over
Africa holds ~21,000 fires, and the old cap kept only those above
~17 MW, so most heat spots faded into empty ground as the heatmap went
out. A rebuild of that many costs ~60 ms, and only in the densest views.