While the proposed plan is an improvement on the existing scheme it is insufficiently bold and does not address all the problems that could be addressed at this point.

I much prefer the road layout given here: http://camcycle.cyclescape.org/media/W1siZiIsIm1lc3NhZ2VfcGhvdG9zLzhhZS84YTQvOGFlOGE0YjcxZTExMzA1NzY3ZDYxNTJkZWEyMzg5Nzk5YjYzYThiYyJdXQ?sha=1b3daa334e733220

This would see the road go through the current location of 137 Chesterton Road and the demolition of at least some of 135-155 Chesterton Road. However, many of those properties are already in poor condition and unoccupied.
The key advantages of this road layout over the one in the SPD are that it reduces the number of junctions between Victoria Avenue and Milton Road from two to one. It also removes the unnecessarily long local access roads and provides the minimal amount which maximises the area available for positive outdoor space.

If that is too radical then the plan could be improved by reducing the local access roads so that the Victoria Road section only continues as far as the junction with Corona Road with a pedestrianised area beyond that and the section from Chesterton Road only goes directly to Springfield Road. This would free up substantial additional area.

I like the proposals for positive gateways into the area.
A foot and cycle bridge from Jesus Green through the present location of Barclays Bank would provide a much better connection between the new area and Jesus Green, particularly as the Victoria Road bridge is too narrow for segregated cycling provision and there would likely be a lot of foot traffic between a new positive Mitcham's corner area and Jesus Green.