Interesting, the lower knuckle IS in fact different for camber control. They did that so the control arms ARE the same. So that means the Demon like all LX platforms have the same non-adjustable control arms that we all replace with AAD parts to achieve a flat camber. The Demon achieves a flat or potentially small positive camber by substituting the bottom knuckle.
The parts people cannot find any different cradle assemblies looking at the “option codes” they tell me. Do you have a part number off your “Demon cradle”?
Here is the Cradle part #'s for 2018 since that is when the Demon came out.
All LX-LC non Hellcat/Demon...........68339965AA.
All Hellcats........................................68339962AA.
Demon only.......................................68339971AA.
These are all different because of the different alignment spec between the different models.
As far as the Knuckles go, the reason why the Hellcat and Demon part #'s are different is not that the Knuckle is different, which they are not, it is because the knuckles are sold as an assembly which includes the lower tension arm bushing and the Demons came with a higher durometer bushing vs the Hellcats.
Hope this helps to explain what you found out.
I can get good help with info as I am blessed with having to know directly & indirectly several of the people in FCA and also many who were part of the SRT department which is now being changed.