DP was CWA's commercial (public) version of their developement system.
It has been sold for a hefty, though reasonable fee and was a 2 way failure:
business oriented developers NEVER generated any acceptable revenus from their products, while 'interested' developers generated a lot of support requests without contributing anything to the platform.
this public version was accompagnied by a tool to assemble and compile SHARC DSP code and do the CWA specific hardware encryption.
Afaik it was licensed to customers for a 5 figure $ value only after individual negotiations.
the (so-called) 'free' SDK is more or less functionally equal to DP, but comes as is - 'developer style' documented (those dudes never seem to have the time to write down what's self explanatory in their minds...) and with an entry fee in form of the purchase of a 14/15 DSP card.
those are the facts - now you may reason about them...
I'll leave out the rant why world class plugins aren't sold as it's becoming boring already...
but those requests to develope DSP specific low level stuff (new atoms) is interesting.
in any context I've read on this forum this is simply VANITY - and there's nothing bad with that, except the fact to not admit it

the fact is there's noone around here who is able to deal with projects on that level. Even John Bowen made compliments to RedMuze for Flexor (which is rearranging existing atoms in new context) and wrote he wouldn't be able to have done the same.
for those who can deal with DSP programming there's Analog's VisualDSP and there are OEM boards with 32(!) next generation Sharcs...

I do not see any reason at all that CWA's economic situation (which is driving the technical one) is related to a lack of developement possibilities.
This may be the low region, but it's already high-end audio processing - it's pro stuff and has to handled accordingly.
If you can't make your way through SDK on your own, you simply don't qualify for commercial developement.
cheers, Tom