>> I still think that a new texinfo command that allows both
>> fractional values and sample strings as column width specifications
>> would be most beneficial.
>
> The simplest change, assuming that sample strings are used as widths
> by measuring their boxes, would be a command that generates a fixed
> horizontal space equal to some fraction of the available horizontal
> width given as an argument.
>
> Perhaps @hstrutfrac{.33} could be a good example for stretching its
> containing hbox to about 1/3 of the available width? This could
> also allow the implementation of @multitable @columnfractions to be
> simplified.
Yes, something like this.
Werner