UE4 - How to release a game for PS4?

No no. The limitation is Sony wanting to prevent everyone and their moma access to exploits and high level access that facilitates the creation of emulators and the like.

On one hand, I don’t blame them.

On the other, the reason I never buy their latest trash console is definitely due to that, in part… for the other part… Imagine playing skyrim without mods for instance.
That’s every PS player out there.

That said. Get something going as a playable demo before you apply. Doesn’t matter what it is, or if it’s finalized or horrible. It just shows that you are slightly more serious than anyone else attempting to get access.
/ is the program even open? It’s been closed for a while, and they seemed to have no intention of opening it back up to indi devs last time I checked it.