Scale Portion of Transform docker does not respect document scale

When working at scale (in this case 1/2" = 1', when I use the "Scale Portion" option on the Transform docker, it will scale the object to full size.

For example, when working at 1/2" = 1', setting the portion to 60" and hitting apply will scale a 10" x 10" square to 1440" x 1440". If I divide this size by 24 (the scale ratio), the square will then be 60"