I debated heavily where to set the parameters for this question, but in the interest of simplicity, it starts when the SH get within eyeshot of Elbaf, ends after they get withing eyesight of another island/settlement after leaving.
Meaning if there's a battle after leaving, but before within eyeshot of another place, the buffs from it would still count, even if the community considers the Elbaf arc to have ended.
Conversely, if they settle at any major island /settlement that Elbaf, the poll ends then.
If the SH with the biggest buff is somehow not obvious, the weakest of those in question (ie, say it's either Luffy vs Ussop, Ussop would win). If that doesn't clear it up (say, it's Robin vs Franky) a 24hr poll on r/ onepiecepowerscaling decides the answer.
This is my first question on here as I only casually use Manifold :| So please, place your bets LOL, I tried to cover all my bases but might have gone a bit tryhard. I welcome any constructive criticism, tyvm.