.5 HCA would be better for an earring. Here’s a chart that Garry H the developer of the HCA is working on. Not sure if it’s the end product yet but you can see that a 40.6 PA should be paired with a 35, 35.5 or 36 CA for best results.
I don’t like the way the arrow heads disappear, but I’m fussy about the details. YMMV