I am sorry for the delay in providing you with a response while I obtained the correct contact information. The USEA Board of Governors is the proponent of this rule change and I have been advised that it would be most effective were you to send your comments to the following e-mail address and to assure you they will be considered: firstname.lastname@example.org by the USEA.
This said, I am also happy to share your concerns with the Eventing Technical Committee.
I would like to add that that all proposed rule changes for the 2016 Competition year will not be reviewed for final approval until the USEF Annual Meeting in January of 2015. There is a great deal of time for comments to be received and all comments will be reviewed. The USEA Annual Meeting will provide many opportunities for open discussion of this rule and it is absolutely possible to revise PRCs right up until and during the USEF Annual meeting.