LSI Logic and VLSI Systems used to do such things in 1980s -- they produced a quantity of "universal" base chips, and then relatively inexpensively and quickly customized them for different uses and customers, by adding a few interconnect layers on top. Like hardwired FPGAs. Such semi-custom ASICs were much less expensive than full custom designs, and one could order them in relatively small lots.

Taalas of course builds base chips that are already closely tailored for a particular type of models. They aim to generate the final chips with the model weights baked into ROMs in two months after the weights become available. They hope that the hardware will be profitable for at least some customers, even if the model is only good enough for a year. Assuming they do get superior speed and energy efficiency, this may be a good idea.

It could simply be bit serial. With 4 bit weights you only need four serial addition steps, which is not an issue if the weight are stored nearby in a rom.