It cannot be harder, and could be a lot easier. Lots (well, relatively lots; this isn’t a research area with millions of practitioners) of people must have bee

It cannot be harder, and could be a lot easier. Lots (well, relatively lots; this isn’t a research area with millions of practitioners) of people must have been looking at that problem ever since Strassen showed the exact value is less than 3 in 1969 (https://en.wikipedia.org/wiki/Strassen_algorithm https://en.wikipedia.org/wiki/Strassen_algorithm), and there hasn’t been progress on moving that needle, so I doubt it’s even remotely easy, though.