Netflix’s Money heist

I might’ve just missed the big part of the plot (i skip a lot lol) but what was the reason for melting the gold chips back to blocks right after delivery? Wouldn’t it be easier to collect the chips, move them in a smaller size and the when things have cooled off then melt them somewhere else? If it has something to do with the idea of ”returning the gold” could’ce they just make it seem like they melted them there. They faked the scenes all the time. I’m lost 💀