The "In QSO with GUI section (circled below) is hard to find and parse.
The location of this section is hidden in the middle of a busy screen. It is hidden vertically between the log and the connected callsign box, with NO white space to separate it.
The font, lowercase, text size is hard to see and read.
The QRZ ? and History and Graph buttons should be a bit larger and prominent.
The QRZ ? button does NOT need a "?".
Please brainstorm some solutions and add to the comments!
Suggestion: Add a QSO timer in the status bar at the bottom of the GUI. (The circled location is just an example. It does not need to be in that specific location within the status bar.)

When connected, instead of putting the callsign in a separate textbox and greying out the callsign above the Connect button -- use the callsign above the connect button as the indicator!
Bold it.
Highlight it in green when connected.
Then remove the additional textbox.
[I have now opened a NEW Feature Request for this idea.] The QRZ feature should be redesigned!
QRZ has a different meaning in Ham Radio. Maybe change the button text to LOOK UP IN QRZ.COM.
It would be super nice to have the browser open QRZ.com in a captive window of VarAC! A. This feature could be configurable in the settings and its location etc should be configurable/remembered.
B. Clicking the button should toggle show/hide the captive QRZ window (without erasing the results once populated). C. Optionally, the results could be remembered and recalled, through a right click menu of a callsign line anywhere in the GUI/datastream.... D. As a practical matter, it might be wise to add a setting to clear cached data after a configurable timeout. But at least it should be cached for the current VarAC session.
E. If it is cached for more than a day, then the web page should be queried in the background and refreshed if the results are stale.