He doesn't use copper foam cooling

Looks like something I'd use to scrub the gunk out of a pot.

It should work.
The goal of a heatsink is to maximize the surface between the two surfaces (i.e. the copper and the air). That's why they have wings to start with, otherwise it would just be a flat piece of copper.

That foam thing just seems to be an extension of that idea, trying to maximize the contact surface in a given volume.

after 1000 iterations, one only sees death

how would something like this be manufactured

the foam limits air circulation, turning it into an insulator that traps heat, rather than dissipating it through convection

Investment casting would be the only way to mass produce it.

It can't work properly because air can't pass freely like with plates

What happened to that copper heatsink that would spin and was in turn, a fan?

Seems like a better idea that a foam (which is hard for air to flow through)

Air can pass freely, it would just act as a dampening barrier for fast-moving air. However this is clearly meant as a passive cooler that don't use a fan. Thus the air will move very slowly due to heated air rising. This slow moving air will not be impeded to any significant degree by the foam structure. Therefore it will work well.

There's one that's extremely low profile that only sort of works as well as a traditional HSF. In reality I don't think the design would scale well and the noise would be pretty bad if it were larger.

Foam is meh becuase it prevents convection, only the top layer dissipates heat, the rest will simply trap hot air inside.

This thing?
youtube.com/watch?v=u2tCnjb6lp8