Da hat Torsten Schaßan leider recht: https://listserv.brown.edu/cgi-bin/wa?A2=TEI-L;b2d25e2e.2403
[…] the usage of <cb type="end"/> […] seems to be tag abuse to me as the definition of cb clearly says 'marks the beginning of a new column of a text on a multi-column page'.
Thus, the presented usage of the element seems to be the exact opposite of what the element is meant to be used for.
Er schlägt auch gleich eine gute alternative Lösung vor:
Why not replace this with something like
<milestone type="end" unit="column"/> ?