yeah low precision quantization is definitely something we want to pursue, but it may not need extra quantization schemes to support them, although we’ll need new data type support. for example, we can have per tensor affine quantization(existing quantization scheme) with Int4(new data type).
In the case of 1-bit precision to {1, -1}, we also need a new quantization scheme since it is not affine quantization. if the integer values are consecutive, e.g. {-1, 0, 1}, {0, 1}, I think we should be able to represent it with per tensor affine quantization and a new INT1/INT2 data type.