If that is true, i wonder if there are perhaps some problems with your ps4?The lag is still horrible all around. No way has this gotten any better... If you find lag (not talking about spikes either but minute long ) of <15 fps acceptable then good for you.
Loading times are still absurdly long... Nothing has improved there. I frequently stare at 2-3 mins loading screens.
I am very sure performance has gotten better with the patches for me. Before the patches, when i was in the bog, the framerate was annoying. The first time i got around crow perch, the framerate wasn't all that either. Everytime i started raining, the framerate dropped badly. I'm not lying when i say this has been a lot less for me. Played all evening today, and there were a few occasions on where the framerate dropped, but nothing grave.
Also, whenever i load a game, it's within a minute and certainly doesn't take 2-3 minutes.