Regarding Gigapress size:
The 9000 ton and 8000 ton have identical platen areas. The 5500 and 6100 ton have 32 cm closer tie rod spacing and 50cm smaller platens along with 30cm shorter stroke and 20cm smaller max die height. The smaller pair have less than half the max shot mass.
The difference in clamp force corresponds to the crossectional area (in clamp direction) of the casting. The front end of Cybertruck will likely have the open middle design we see in Model Y. However, to achieve the flows needed across the casting, the open middle does start out life with metal, adding to clamping load. Still, this does likely does not need the same capacity as the much longer rear casting.
There are shipping docs showing another incoming Gigapress.
The melting oven is separate from the press and Tesla could potentially use one oven to feed multiple machines.
Recent Joe video showed recycling of aluminum blocks which could be remelted test castings.
