If I may, this is definitely a minor suggestion, but sth that would work like a passive "Sage jutsu chakra" would be a very nice touch.
I know this is not my topic, but Sage Mode for characters is... an amazing idea. I would definitely like to see it with one of the two options:
-Hiruzen Sarutobi passive: After Death uses a skill (in this case, Sage Mode)
-Clones. Almost every main has clones, I think Earth is the only exception. What if we got sth like those clones being "infused" with sage chakra, and giving the power to main after they are broken? This idea need a lot of work, but as a draft, it looks nice to me. Wind and Earth main will need other solutions though.