Maybe you could put the Emperor's arrival before the journey to the Sarlacc begins, and then after they flee Tatooine instead of cutting to the Death Star you can go straight to the Rebel Alliance gathering, as Yoda and the Emperor's arrival will have happened already.

However, while all this might sound feasible, there are real risks of upsetting the pacing of the story. Going straight from Jabba's destruction to the Rebel meeting is a bad idea. You need a soft scene in the middle, which is where Dagobah is at the moment.