Awesome. Let me know if this lives anywhere else, like GitHub. This is only place I’ve been able to find it, and I’d love to know more as it happens.
What Frank said. Quite impressive you dug that deep to discover this bug in WebKit.
You should be in WordPress core!
User error should not warrant a 1-star review. Theme Switcha couldn’t be any more simple to use. Click on the desired theme within the plugin’s Settings panel and you’re instantly launched into a new cookied session within a new tab. What’s so difficult?