I think my PRS Alpha was among the first to get the echain as included equipment. When I ordered my machine back in 2012, the echain wasn't standard. I didn't know anything about it at the time but when I got the machine and started hooking it up, I realized how important the echain would be so I called Diane (she used to be the sales person at SB) and ordered one. I think the price was pretty high, more than $500 for the two chains and trough carrier. I received the parts a few days later and a note from Diane that Shopbot decided to include the echain and the echain trough as standard equipment for the PRS Alpha. I didn't get charged. Very nice!
Seven and a half years later and the machine is still going strong. The echain is a required bit of kit in my book.
ShopBot Details:
2013 PRS 96x60x12 (Centroid upgrade)
4hp Spindle
12" indexer
Aspire
Rhino
Fusion 360
Ferrari 360
Prusa MK3S+
Prusa XL multi-tool