My understanding is that a Pro 580X is just a rebadging of the Pro 580, which is from mid-to-early 2017, and all the 5xx series is just minor spec bumps on top

My understanding is that a Pro 580X is just a rebadging of the Pro 580, which is from mid-to-early 2017, and all the 5xx series is just minor spec bumps on top of the 4xx series.