DI works best with boat movement because of the thin shape of the DI sound pulse ...
2d is suited for stationary boat control ...
And of course the 83kHz 2d Sonar cone shape (60°) is wider than the 200kHz Sonar cone shape (20°) ...
So your theory of using 83kHz 2d would indeed allow staying off the fish somewhat and still see the fish on the 2d Sonar view ...
The challenge is that the fish may be forward, aft, starboard, or port of the transducer and still show at the same place on the 2d Sonar view ...
Rickie