General Fusion changed their plan last year. The acoustic compression scheme, and the use of a spheromak plasma, are out. They discovered they have to limit the magnetic field to about 100T or else the induced currents start vaporizing the surface of the imploding liquid metal. This would be a disaster, as the metal vapor would have poor electrical conductivity and would penetrate into the plasma.

Confinement in the spheromak was also unacceptable; fast electrons were lost too easily from the edge, causing too much cooling.

Instead, the new scheme compresses more slowly, and compresses a spherical tokamak plasma. This scheme will have a solid post running down the center of the plasma, and the metal will implode from the sides at lower speed. The burn will take about 1 millisecond.

I am skeptical of this approach, since the center post will be exposed to extreme conditions (average neutron fluence two order of magnitude higher than in conventional fusion reactor designs) without a thick layer of liquid metal to shield it. The non-acoustic compression scheme also means the reactor vessel will have to withstand extreme pressure.