Alright… yesterday I tried to make the Obi Wan VS Vader sequence to look like this: https://www.youtube.com/watch?v=mm4JEZudf0c

Basically we start with DoF when we see Vader in the hallway, and then we follow the music. The main change is that Luke, Han and Leia leave the DS with the Falcon while Ben is still fighting. So Luke does not witness his death, but he feels it (with the shot of Luke looking up just before the Tie Fighters approach).
It sounded cool, but the great problem is that the trio leaves the Death Star without Kenobi, and without knowing he is dead. I tried to add Ben’s voice saying “Run, Luke, Run” while he is fighting Vader, but it didn’t sound ok.

Unless someone has ideas to give the duel more rhythm, I’ll keep the original duel with some music tracks…