> Makes sense.  Then what about adding a new option that defines
> the minimal number of columns each window should have after split?
> With a name like 'split-columns-threshold'.

(Caveat: not following this thread.)

Just a comment that a name such as `*-threshold' doesn't
tell you whether the threshold is a lower or upper bound.

Usually, a word such as `min' or `max' in the name is
more helpful.

(Of course, regardless of the name, the doc string should
anyway spell things out appropriately.)