I know Sidious went to the Jedi temple once Vader had killed all the Jedi there, but what would have happened if Sidious had gone with Vader and the 501st to the Jedi temple to aid in the slaughtering? How would that have affected the Sith?

The whole point of Vader slaughtering the Jedi was to build his connection in the dark side. Would he have been weaker if he did not have a chance to kill every Jedi? I would assume he wouldn't be weaker because I think the act alone would bring him closer to the dark side, not the number of people he killed.

If Sidious helped in the slaughter, would he have gained more power? I would assume he would get a bit more powerful, but I feel that his duel in his office was more than enough to bring him to his peak at that point in time. Any extra kills wouldn't have changed much for him, except for maybe killing Yoda.

What are your thoughts?