finished Adventure Mode (2 weeks ago allready) and haven't played much since them. Survived in Survival Mode up to day ~160'ish, and I'm only missing out on Wes.
I tried to get him by searching Adventure Mode World 1 over and over again, just running around and see if his area is there...somewhere, but it takes sooo much time, 1-3hours to unlock the whole map, that it just sucks to search for him. The problem is, he has a spawnchance of 1%(!). I don't know what the developers thought by doing this, but it's totally senseless, since you not only have to find him, but you have to kill a lot of monsters, too, so you need preperation, which needs another tons of hours, and don't underestimate the harsh Adventure Mode Environments.
On the PC version you can cheat and unlock the whole map to see if he is there, decreasing the time to find him to a minimum, but on the PS4 Version you have to search for hours in one world, before you know if he is there or not, before you can "restart" adventure mode and try to find him again.
So if you are not lucky to find him after 1-5 tries, and need instead 40+ tries, don't even think about going for Wes, the 120+ hours of "Gameplay" are not worth it.