At this time we don't have something like
\begin{tabu} spread 0pt{XXX}
One & Two & Three
\end{tabu}
It is useful to make all columns have a width equal to the widest cell of the table (similar to columns-width=auto in nicematrix package).
Maybe we can call it width+=0pt in tabularray.
At this time we don't have something like
It is useful to make all columns have a width equal to the widest cell of the table (similar to
columns-width=autoinnicematrixpackage).Maybe we can call it
width+=0ptin tabularray.