As Ferdinand Pointer pointed out, regulating hammer weight precisely is
one way of regulating the touch precisely. However, even the finest
concert grands used on stage in the heyday of reproducing player grands
were not regulated this way, as can be attested to by myself and others
who have changed those very hammers used at the concerts. Like they
say, there's more than one way to skin a catfish.
As far as the treble notes without dampers are concerned, there is no
danger of them giving trouble and playing too loudly during a soft
pedaled passage, in the real world. Their perceived volume by the ear
is in their initial impulse. That's all one can say about that. They
do not sit there and ring audibly in sympathy anyway. That's why they
don't have dampers; they don't need them. And re-weighting their
hammers is an effort to gild the lily. They are voiced, not weighted,
for what they are expected to do.