Wirelessly posted (Mozilla/5.0 (Linux; Android 5.1.1; Nexus 5 Build/LMY48B) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.93 Mobile Safari/537.36)
JetBlue.com still acting up, but the Mint fares are now viewable on ITA. It looks like the $599s are available on BOS-SFO, at least to some limited extent.