Perhaps.

And to be clear, I have no doubt that it could heat the copper, I just wonder if it can prevent the hot liquid copper being extruded from instantly melting the copper below it that was previously laid down.

I did some soldering with gold recently and was shocked at how well it conducted heat from one side of the part to the other. I’d get one wire attached to a contact and then when I brought a wire to the second contact, the first would melt and that wire detached.

It was frustrating.