Okay now you're just pulling stuff from nowhere. I don't see the spoilers say it was some seastone giga knot. Whatever material it is, it's a piece of rope that contained what's the equivalent of a small nuke in the One Piece world. It's not going to make sense no matter how you spin it.
CoC scaling is always clumsy because like this shit just blows trees away… as in if we are calculating physical force, this shit can’t even break a building… If a nuke can’t even break a building then what are we even talking about?
CoC scaling has always been weird because of this shit… how does it actually affect physical objects like OBJECTIVELY?
Anyway Joyboy is from the ancient Kingdom, the ancient kingdom with Super science above Vegapunk science… so super ropes are possible
And Unbreakable fabric is already canon in the manga and was introduced 400 chapters ago
Anyway I am assuming the knot has to be strong, it’s not stated anywhere but I mean it’s been 800 years, and this knot hasn’t lost tension in 800 years so it must be special already