in the ozcot.xml is ignored.
If you have a 3meter deep soil then the roots will grow all the way down to 3 meters. The only way to restrict the roots is to shrink the profile.
nb. It is well known design feature of ozcot that xf and kl for cotton have no effect in restricting root growth.
See attached simulation (created using Apsim 7.6) see rtdep column of harvest output file.