For some reason, the "callsign" gauge just above the speed tape(s) to the left of the MFD wasn't included in the virtual cockpit.

To add it, open your panel folder and add the following line to the [Vcockpit01] section of the Panel.cfg file:

gaugeXX=Virtavia_B-1B!CALLSIGN, 118, 87, 75, 31

Change the XX to 21 or else check that all of the gauge lines in the [Vcockpit01] section are sequential.
Make sure you use Notepad to do your edit and you're done.
I haven't noticed any changes in frame rate after adding the gauge, so maybe they just missed it?