While on the subject of circling I was informed recently by a Boeing Seattle Flight Training simulator instructor that the 737 FCTM newly recommended configuration for an all engines circling approach is to have landing flap in position at the beginning of the circling approach in order to be certain to be stabilised before final. This means staggering around the circuit at Vref +5 fully configured.
The fuel consumption in that early config would be horrendous (let alone the ramifications of an engine failure with landing flap in level flight) and makes one wonder the real hidden reason for this curious policy. For decades 737's have been conducting circling approaches in a Boeing recommended configuration that has apparently stood the test of time. Then suddenly something happens and the policy changes. Legal implications, maybe?