It would be very handy if vMixCall inputs had visual indicators in the main interface if the caller's camera is off, microphone is muted, or if the call is disconnected. It's a bit cumbersome to check this in the heat of the moment in the Call Manager window when you just quickly want to make sure the next caller(s) are ready and they have their camera and microphone turned on. I'd suggest there could be a small text box on top of the call input box saying "MIC OFF" or "CAM OFF" or "NOT CONNECTED" if any of those cases were true.

For connection status, that's true, but it would be nice to have a quick visual indication of microphone & camera status somewhere easily visible. Personally I'd prefer to see that in the Call Manager window, perhaps as icons in the header.

We usually ask guests to connect before events, so that we can check the setup before going live. Sometimes however, they mute their mic while waiting (despite us telling them we'll manage that in vMix) and then, 15 minutes later after connecting several other guests, the only way to check their mic status is to scroll back through the call manager log and try and spot the 'microphone muted' message. Red 'mic muted' or 'camera off' icons in the header - alongside the call number - would be easier to see.

@doggy - you're going to tell me that it's possible to get mic / camera status with a script, right ?!

I like the idea of a visual reference in the thumbnail. But what happens if you collapse the thumbnail.
Maybe it's best to stick with the call manager. Details are available there.