Has anyone considered construction of the CPA encoder? I wonder if an existing encoder chip can be modified for the purpose.
Ideally, it would be interesting to create as envisioned, a truly NTSC-CPA signal. Y', Cb', Cr', is available from many consumer devices and this would simplify the construction of the quadrature modulation and luma adder.
The R-Y axis would have to be inverted each field and the CPA sync would have to include the flag to properly correlate and signal the color field.
Any thoughts? It may be interesting to have an "official" competition to see who comes up with the best design.

Maybe the prize could be, say, an RCA CTC-11 or something like that?