Ævar Arnfjörð Bjarmason [off-list ref] writes:
FWIW this wasn't a "while at it", it was critical to making another part
of that topic work at all.
Perhaps it was critical within the approach of the topic took, and
if a different approach was taken or the scope of topic was reduced,
you would have avoided it. I would still consider such an unnecessary
change an unwated "whilte at it".
The moral of the story is that the topic took too big a bite to be
done without causing unnecessary mistakes like this.