The ability to manually control support locations is fantastic. But having to add support by individual cylinders is time consuming. For example, I'm printing this prosthetic (http://www.thingiverse.com/thing:261462) which has a "palm" piece that requires support. I don't want to use automatic support because it puts support into some screw holes and small arches that don't really need it (and which are hard to remove). So what I want to do is manually generate support for the palm area, which is relatively large.
Doing this with the current controls requires clicking every point in a grid every 4mm (or so), covering an area of about 60x50mm, which is a lot of fairly precise clicking. Instead, what I'd like to do is drag a rectangle covering the area that needs support.