It's a weird one, indeed - according to IMT, SMO on Windows doesn't seem to be supported with FCoE, but is supported with FC.
It used to be the case that any SnapManager product was supported only if SnapDrive was supported in a certain combination of protocol & host OS.
Also, only until recently FCoE & FC wasn't differentiated at all (there was a general comment stating FCoE is supported wherever FC is supported).