Pattern overrides, one year on

A synced pattern with overridable blocks, used on forty-one pages, and what a year of editors using it produced.

what worked:
  the layout changed once, centrally, and forty-one
  pages followed. that is the whole feature and it
  delivered.

what did not:
  an editor needed a second button on one page. the
  pattern has one. they detached the pattern, which
  removes it from the synced set silently.

  four of forty-one pages are now detached copies,
  and nothing in the interface indicates that.

Detaching is a one-click operation with no confirmation and no subsequent indication, which means a synced pattern silently becomes a fleet of copies. The check is a query for blocks whose pattern reference is absent, run monthly, which is a script nobody would write until it has happened.