They have retimed them – at least, the northbound green from Dartmouth Road is certainly a lot longer.
Living on Dartmouth as I do, the traffic impact isn't as bad as I feared when I got back from a week away on Friday to find the South Circ blocked off. Bad, yes, but not that bad. I think much of the eastbound South Circ traffic that knows the area is carrying on through Sydenham and up Perry Hill to rejoin in Catford, thereby missing the often-congested Blythe Hill section anyway.