Idk man i feel like Harald would’ve told gaban to eat the fruit if that was the case and didn’t rocks say it’s full potential is when an ancient giant eats it?
I'm not talking about Gaban eating Loki's fruit specifically
What I'm saying is that we are all agreed Gaban and Shanks heavily wounded HK Harald multiple times, yes? We saw it in canon and then Gaban said so himself.
If Gaban and Shanks could inflict permanent damage on an ACoC-wielding immortal, they would've killed Harald. The only issue was regen — they couldn't stop it and Harald is already a top-tier, meaning he'll kill them and anyone else eventually. Loki could bypass it.
And for the record, as long as Harald was being controlled, even Loki actually
couldn't permanently halt regen. Harald was still recovering; he only killed Harald once Harald lowered his defenses and he could take him out in one hit.
This is the treasure of Elbaf, Harald wouldn't have given it to a human. This fruit probably has something to do with unlocking the Galley La giants etc... so there are specific purposes for the fruit outside of combat which likely require someone like Harald or Loki.