A straight up -Damage Taken% roll might be useful for a few things if Corsair ever receives the ability to keep three rolls on folks instead of two. It could be a relatively low amount, but able to go past the cap due to being calculated before or after it, similar to Barrier Tusk.

Really, it would have to circumvent the cap somehow because you'd have to be giving up some really epic underpants for reducing the changes in your -MDT% or -PDT% set to match one of the right Corsair rolls for a situation.