def METHOD_NAME(self):
    """
    Recalculate the derived position and send subscription updates.
    No-operation if the original signal is not connected.
    """
    if not self._derived_from.connected:
        return
    value = self._derived_from.get()
    if value is not None:
        # Note: no kwargs here; no metadata updates
        self._derived_value_callback(value)