Question about HW4 Controller Upgrade

I am thinking of upgrading to the new ALP HW4 Control Unit. I saw somewhere that it works with the NR-DSP heads. I have a NR-DSP for my front radar detector, but I'm running an older non-DSP head for rear detection. Will that be a problem? Will I have to upgrade my rear detector to a DSP model for it to work with the new controller? TIA.

HW4 CPU's support both the original NR + NRDSP but some features will not work with the old Analog NR units such as the Assisted Radar Filter (ARF) which is available for Net Radar DSP to help filter out radar-based BSM’s