Feature request: diversity heatmap from polygons

As it stands, the FSC BRT can only create biodiversity heat maps from point data. It would be nice if it could be used to create heat maps from overlapping polygons. There is no simple way to do this right now without converting vector to raster, then unioning layers, etc… The goal is to have something that looks like the attached picture

That’s a pretty map. We wouldn’t incorporate this into the BRT as it is so radically different from the purpose for which it was designed, i.e. to generate grid-based ‘atlas maps’ from point data. This would be a candidate for a completely new tool sometime if there was enough demand for it.

Might you have any insight into doing this in QGIS either using the BRT or just the base QGIS program, given your speciality in heat mapping?