pointsWithinPolygon performance improvement

I've hit a really slow path of the code here. (a lot of points 65606 (only +/- 350 in each polygon) and 475 polygons)
I wanted to find points within each polygon and calculating an average of some properties.

This code stall the browser and making it unresponsive

for (let zone of zones.organisationUnits) {
  const ptsWithin = turf.pointsWithinPolygon(
    { type: "FeatureCollection", features: points },
    zone.geometry
  );
  const rwis = ptsWithin.features.map(r => parseFloat(r.properties.record.rwi));
  zone.rwi = rwis && rwis.length ? average(rwis) : undefined;
}

I've modified the code to first filter on bbox then only calling pointsWithinPolygon on remaining points and now it completes and quite fast (and stole the inBBox function)

for (let zone of zones.organisationUnits) {
  const bbox = turf.bbox(zone.geometry);
  const pointsInBbox = points.filter(pt =>
    inBBox(pt.geometry.coordinates, bbox)
  );
  const ptsWithin = turf.pointsWithinPolygon(
    { type: "FeatureCollection", features: pointsInBbox },
    zone.geometry
  );
  const rwis = ptsWithin.features.map(r => parseFloat(r.properties.record.rwi));
  zone.rwi = rwis && rwis.length ? average(rwis) : undefined;
}

May be that's an optimization the pointsWithinPolygon should have built-in no ?

you can see it in action here (click on Map)

Start at the pointsWithinPolygon entry point and compare its current work with the reported bbox prefilter using turf.bbox and inBBox. Reproduce the large points-and-polygons case from the issue, then verify that the built-in path avoids the browser-stalling slowdown while preserving the points selected within each polygon.