The entire block should be in the second column but it is instead being split across the two columns. This is a problem with the test. It should be adjusted to give the same results regardless of how the balancing algorithm works.
vertical-lr/border-padding-pagination has the same issue.
Also vertical-rl/border-padding-pagination
<rdar://problem/16656293>
This is a blocker for turning the new columns on.
Changed my mind. I don't think this has to be a blocker. It is inferior balancing to the old code, but we can track it as a REGRESSION after turning the new columns on I think.