There is a feature in the latest WSJT-X called "Wait and Call" that can be very handy. If you can't decode a station, but you know he is there, you can have WSJT-X automatically call him once you do decode him. You need to enable this function by putting a checkmark next to "Enable Wait features"
on the Settings | General tab.
Just now I could see that E44OM was on 15-M SuperFox but I could not decode him because of QRM. I set up the Wait and Call feature and after a few minutes my station suddenly began transmitting because I had just decoded him. I did not work him that time because the QRM was still there. But, this means you don't have to just sit and stare at the screen waiting to see if you decode the station. Or for JTAlert to notify you (and when that happens you miss the first chance to call as you are trying to find the Enable Tx button or are away from the radio.)
Wait and Call
Wait and Call is useful if the station you wish to work disappears
for a time, perhaps in a deep fade. To enable the feature, click on the
DX Call label, which will turn red if a callsign is present in the
DX Call field. When the station is decoded again sending a message
containing CQ, RR73, RRR or 73, you will call him automatically up to
three times. Any manual intervention, such as pressing the Halt Tx
or Stop buttons, will disable Wait and Call and give you the
normal manual control over the QSO.
This feature is a bit tricky in SuperFox as you need to click on the DX Label first and THEN enter the callsign in the DX Call field. I could not find in the manual where the DX Label was but found it by accident. I have marked it in the screenshot below. It is the box that says "DX Call" right above where you enter the DX's callsign. Once you click on the "DX Label" it will turn Red and you can then type the call in the field below the label.
There are other "Wait" features - Wait and Reply and Wait and Pounce. You can see the description of them in the online WSJT-X manual at Section 10.4: