I personally think the definitive best way to pace it would be:

-> Original opening with Padme assassination attempt
-> Deleted Scene of Padme at the Senate Hearing (it’s a good scene on its own, and it will help calm down the intense opening for a smoother transition
-> New establishing shot (fanmade -> Coruscant Exterior, a Jedi-worthy, subtle soundtrack
-> AOTC Flashback incorporation (color graded, Anakin’s voice pitched down, deepfake incorporated)
-> Chancellor Palpatine’s Office, Padme and Mace Windu talks -> suggestion of Obi-Wan and Anakin to assist
-> Anakin & Obi-Wan in elevator

This introduces all main and side characters (except Dooku) in the opening ten minutes, would provide smooth transitions between the hard opening, but most importantly; a time span of what could be a full day before we see Anakin & Obi-Wan again after their Flashback scene, so for the audience to disregard the subtle changes in actor’s age and differences between the two very different shooting schedules.

My two cents.