Alan W wrote...

It would be my understanding, that extensive further manipulation of
this steel would be necessary to forgeweld the plain steel onto the
white or blue steel, and that this process is, in addition to the hard
steel, is the real value in japanese high end tools.

Absolutely true, of course. Quality tools don't make themselves! (G) The
smith definitely earns his credit.

Although tempting, a solid blue or white steel tool would be quite
brittle according to common espoused literature, and the job of the
soft steel is to provide shock resistance and support for the super
hard layer.

It would be a waste, given the high relative cost of the material.
However, it is almost certainly possible, technically, to make a fine
blade from solid white or blue steel, if by no other means than
differential heat treatment. That doesn't necessarily make it a good
idea, though. The laminated design has real merits that can't be
duplicated well by other means.

Jim