Comparing odc.stac.load and stackstac for raster composite workflow

Alex can you explain what this code is doing? I thought it would apply the mask for all of the different values in field, but it’s not working as I expected. Specifically, the CLOUD_SHADOWS are not actually being masked. Here’s an example scene, plotted via

ds.scl.plot()
cloud_mask.plot.contour(levels=(0.5,), colors='w')

You can clearly see the cloud shadow regions (confirmed to have SCL value of 3) outside the mask contour.