I am not familiar with the real 777's CDU, so I 'm not certain of its capabilities. It is certainly different from the A320 and it 's also not the same as the 737, as there is no radial dial in the 777's cockpit, that's all done from the CDU. I think you mean the ND's display dial, but I 'm not certain that it's tied to the CDU IRL. The current implementation does work, but its indeed very basic and could use some attention. Sidi762 has been doing some work on the CDU, but I don't know how far he stands atm and if he is still working on it. There's a lot to be done in the 777. Please do feel free to contribute in any way you can
Kind regards,
Isaak