You can make CD-3 with the raw components, if you're into that, the raw components are still "exotic" but much much less so and more common reagents, you can get through chemical suppliers. Failing that CD-3 can be had via India and China chemical companies, probably easiest to do that via Alibaba.com
CD-3 can be precipitated out of ECN-2 developer part B concentrate fairly easily too, into pink powder-like crystals (once dry).
There's also 2 different forms of CD-3, so you'd need to change the weight amount you use to match etc.
CD-2 is used for ECP-2 only iirc, motion picture print film. CD-3 is RA-4 and E-6.
Thank you. I think it won´t be difficult to order these components.
Yes, you are right: E6 uses CD3 and not CD2, CD4 as I thought.