Thank you! Yes it does work!
On the 7 Plus I'm able to access all 4 cameras this way. This is what I get and it works perfect:

(
"<AVCaptureFigVideoDevice: 0x12db72c40 [Back Camera][com.apple.avfoundation.avcapturedevice.built-in_video:0]>",
"<AVCaptureFigVideoDevice: 0x12dbeb240 [Front Camera][com.apple.avfoundation.avcapturedevice.built-in_video:1]>",
"<AVCaptureFigVideoDevice: 0x12dbe1b20 [Back Telephoto Camera][com.apple.avfoundation.avcapturedevice.built-in_video:2]>",
"<AVCaptureFigVideoDevice: 0x12dbe6bf0 [Back iSight Duo Camera][com.apple.avfoundation.avcapturedevice.built-in_video:3]>"
)