Ah right - I also forgot that you can configure that node to accept the lat lon by msg properties - eg
Then you can just set it every time you call it.
maybe like this
[{"id":"f8ce24246794a0f0","type":"worldmap","z":"c31385261656417b","name":"","lat":"","lon":"","zoom":"","layer":"","cluster":"","maxage":"","usermenu":"show","layers":"show","panit":"false","panlock":"false","zoomlock":"false","hiderightclick":"false","coords":"false","showgrid":"false","allowFileDrop":"false","path":"/worldmap","overlist":"DR,CO,RA,DN,HM","maplist":"OSMG,OSMC,EsriC,EsriS,EsriT,EsriDG,UKOS,SW","mapname":"","mapurl":"","mapopt":"","mapwms":false,"x":840,"y":375,"wires":[]},{"id":"57a6eb9d710dcee9","type":"flightradar24","z":"c31385261656417b","lat":"payload.lat","latType":"msg","lon":"payload.lon","lonType":"msg","name":"","x":445,"y":375,"wires":[["0436ed4c8ce5abe5"]]},{"id":"0436ed4c8ce5abe5","type":"function","z":"c31385261656417b","name":"","func":"msg.payload.alt = msg.payload.altitude +\" ft\";\nmsg.payload.speed = msg.payload.speed +\" kts\";\nmsg.payload.rateOfClimb = msg.payload.rateOfClimb * 0.3048;\nmsg.payload.iconColor = '#910000';\nmsg.payload.ttl = 300;\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":615,"y":375,"wires":[["f8ce24246794a0f0"]]},{"id":"5de9e7c3215a34e9","type":"worldmap in","z":"c31385261656417b","name":"","path":"/worldmap","events":"bounds","x":120,"y":375,"wires":[["aac697feccb00023"]]},{"id":"aac697feccb00023","type":"function","z":"c31385261656417b","name":"","func":"var la = (msg.payload.north + msg.payload.south) / 2;\nvar lo = (msg.payload.east + msg.payload.west) / 2;\n\nreturn {payload: {lat:la, lon:lo}};","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":270,"y":375,"wires":[["4ec15beaf9f9200d","57a6eb9d710dcee9"]]}]