Custom doesn't mean it will be useful for developers running multiplatform games it can be something only useful for first party studios developing games on the platform. Functionnality been on one platform but not the other if it is not very easy or nearly automatic to use will be only use be first party studos without the pressure to release on another perform.
https://tekdeeps.com/ps5-does-not-use-rdna-2-architecture-has-sony-failed/
On this message and another one he said there is some unique functionnalities.
It doesn't mean it will help in multiplatform game at all. Imo the custom features are only useful to first party devs out of things automated like cache scrubbers.
Microsoft decided Xbox Series need to fully support Direct X 12 Ultimate. Sony does not have any needs to have the full feature set of a PC API.
For the moment on my side this is not if the XSX will prove it more powerful hardware but when? How much time they need to unlock the XSX power. I am like Saint Thomas I need proof to believe something.
After the games I want to play are on PS5 this is more important than the power of the console.
EDIT: T
he search of secret sauce reminds me of misterxmedia. PS4 Pro had rapid packed math with double FP16 and it was less powerful than the Xbox One X. I don't believe any secret sauce giving some advantage to Sony or custom feature doing the same out of maybe help first party to do better games.