I use a PS4 Pro. Using GFX in HD not 4k. Too much in game stuttering. In places the game GFX are very cartoony and not as good as TSW2, too much bloom and contrast. I can't even use 4k because it runs very slow, and stutters and even on HD my fan goes nuts, another thing which has not been sorted. The intentions are there, but it still needs work. Yes it is good, it has potential, but its not there yet.
Considering that there is still a lot of people using PS4's, it should play better than what it actually does. I have seen poor frame rates on live streams, so no its not actually the PS4 its the in game optimisation
Running on PC ultra and averaging 70 - 80 fps… only have noticed a few micro stutters when running Javelin on a high speed run. The programs is running much better on my rig than TSW2. But of course my PC has the ummph to give to the game. I am afraid that older consoles are going to limited. Not trying to be obtuse, but upgrading hardware and systems to be able handle newer titles has been the progression of computing and gaming consoles ever since they came out. Designing software to work on generation old hardware forgoing the benefits of current generation hardware has never been a great strategic business plan.