Thanks for bringing more ideas to the table! I have a few more thoughts about this.
I can’t say I really see the resemblence in the case of Vakama’s anvil, but being a forge in general vs the great furnace I can’t really object to, since it’s not something we can differentiate at the moment, so it could go either way. I simply figured great furnace was the most representative one.
Oh certainly. I agree that it most likely gets inspiration from the mandibles/disk launchers, and while it would explain some of the Ta-Metru disk symbol, the semi-circles would remain unacounted for. And I also agree that it deviates from the geography connection. Overall I think the furnace and smoke/cloud explanation fits the best for Ta-Metru disks. Also the great furnace kind of resembles the disk symbol.
That may very well be. Check out the other version of this render, where the nodular nature of Ga-Metru is even more prominent:
There are even semi-circular platforms, which fit with the large semi-circles on Ga-Metru disks.
Nice observation about the metru-assigned gateways in front of Great Temple! Likewise, I was unable to find depiction where the bridge had extra circular platforms on it. But if we explain that by general stylization and went with the coastal idea for the semi-circles, then the Ga-Metru and Ta-Metru coastlines could fill that role:
