Without pixel scaling btw (Flower Capital is also as large as Onigashima).
Red circle = Flower Capital
Yellow circle = the exact same size of Flower Capital
Orange circles = the mountains comparable to Flower Capital which are, according to you, just "rocks".
The main-land on this region has ENOUGH space to fit 3 - 4 Flower Capitals, it's that large. The hole is exactly beneath Onigashima, so I couldn't draw the yellow circle exactly there but if we look at this panel, it's clear how large the hole is:
The same kind of mountains, as I highlighted above they are clearly large, are massively dwarfed by this hole. On the top right corner there's an actual mountain range of multiple mountains being dwarfed by the hole as well - and that's just the surface, without accounting the actual depth of this hole, destroying lots amount of main-land.
Now I wonder what kind of mental gymnastics you will come up again, to weasel your way out of it? You know, I should have just ignored your ignorant ass way back then but since I have the change to crumble your argument apart, I'll just do it.