There was a lot of discussion in AL's 2013 robot inspection thread about bumper reinforcement & attachments. I think the upshot of it was a "robust attachment" could be stiffen the bumper as long as it function as the attachment & other bumper rules were not violated (such as weight). So it seems you could use Pink's method as part of the bumper as long as the attachment points on the robot satisfied the frame perimeter rules & the other bumper rules.
Of course in 2014 the GDC got real particular about the bumper definition. Us mortals will just have to wait & see what 2015 brings.
