I appreciate these sort of questions are not really what Balsa was intended for but exploring what is possible within the available parameters is what flying has always tried to do.
I have discovered that is it possible to fly right round Wirraway Island flying low outside the red line but the same techniques do not work round Rovin Harbour.

The next challenge is to design a plane that can round Wirraway twice non stop. Endurance electric flying is quite a complex balancing act between air frame aerodynamic efficiency and battery weight.

Using unguided rockets I have achieved well over 3000 m altitude and over 1000 km/h.

Whilst this serves no useful purpose other than test the limits of the game's programming it is an interesting exercise in experimental problem solving.
It would become whole orders more involved, and realistic, if structural limitations were included.