I overcooked the samples a bit just to make the effect more noticeable. I usually edit my photos much less strongly than that.
Also, the appropriate size halos vary depending on the display size. If you're viewing on a phone, the radius needs to be larger to not be noticeable. If I print them out A3+, though, the halos fade away and my brain interprets them as contrast in the original scene.
Should I adjust my samples?