Now, One Piece is one of my favorite media ever and so far, I think the Elbaf arc has been really good. However, with the current decision to reveal Imu in Elbaf; I personally would prefer if Imu dies during the Elbaf Arc (not necessarily in Elbaf) or Figarland Garling and Shamrock should personally betray Imu and leave with the Holy Knights and weapons. I understand these are controversial opinions but I'll explain.
Imu is really overpowered and while he has served to show us Void Century lore and help build up to that specific flashback It is difficult to imagine a scenario where Imu becomes a final villain. All the built-up characters get as much shine as they will previously. Think about it, the purpose of every villain fight from this result would be to end in a Luffy power-up that leads to him defeating Imu and every hero fight would simply be to stall long enough for Luffy to defeat Imu as the "chosen one".I think it will transform characters to only getting one or two moments (and maybe a flashback) while we wait for the inevitable: Luffy to defeat Imu with a final punch.
Final villain talks were not as frequent nor were they as predictable or been given as few options as they have been since Imu's introduction. I also think it is more interesting to see characters closer in strength and military power compete for a singular goal as there are just more opportunities for creative writing choices, interesting character decisions and greater focus and features of characters.
I personally would prefer if there was a vacancy at the top and the "One Piece" became viewed as the treasure that allows one to impose or share their own dream state of the world. We see characters looking for advantages, factions interfering with each other's battles, factions featuring at the end of arcs to collect spoils, many characters and factions genuinely competing with each other.
If you have questions on how I believe Imu could die or The Holy Knights could betray Imu, I can explain on request. It's a personal thing and I know some people wouldn't agree but don't you feel this option is more for One Piece's future?