I have found more incompabilities with the new Panasonic series as well (also seen in the V20). The Dune Media Players show the same colour decoding errors (HD being decoded using SD matrix). There is no workaround, sending RGB is the same as YCbCr. I believe the Dune was the Sigma chipset. I am wondering if the issue is compatibility between Sigma chipset and the Panasonic decoding. Not sure if the Sencore used the Sigma chipset.
The same Dune Media Player with the Pioneer 8G/9G sets did not show the decoding error. So there is something there. Maybe someone close to Panasonic can bring it up with them.
The Dune Media Player had the problem with last years V20 and this years U30.