Sadly, I have to cancel.
Apparently the chain tensioner is different between the 2-speed and 1-speed and the only one they had in stock was a 1-speed. I managed to limp 2 miles with no derailleur this morning, but not gonna work for SF2G.
Amusingly, while researching this part, I found a site that sells a variety of after-market tensioners in expensive materials of your choice, from machined aluminum, at an affordable $225, up to carbon for $650 (for which price you could instead get a Di2 rear derailleur).