Be tough to tell if it were hidden. At zero delay it shouldn't read any different. I'm sure you could build a remote access delay adjuster. Use the stereo face as a screen and the buttons to adjust. Run the "exposed" wire through a grommet with the wires coming out in between of a faked double thickness panel. Personally with all the adjustable buttons and stuff I don't think it would be much of an advantage. Heck, I don't even run a trans brake.
Doug