It may not be turbo but it's still GDI, so it will still suffer from the crusty intake valve issue. I had a peek at my intake valves after just 18k miles and I was surprised at the amount of gunk built up on them. So one or two catch cans would be a good idea if you want to go that route. Alternatively you could just route the PCV system to atmosphere and forget about the issue altogether. That's the route I took. People will argue the pluses and minuses of doing that all day, so you can search for threads on it if you want and come to your own conclusion. Here's a couple to start you off:
Since I saw so many questions and had some myself and nobody ever had pictures, I decided to take some as I did mine so people know what all is involved. I'm not good at holding peoples hands as they do stuff so this is a basic how-to on the process. It is somewhat of a pain in the ass so if...
If by chance you do want to go with oil catch can(s), I happen to have one, barely used, that I'd be willing to let go for a good price.
Also, just for future reference on where to post, 2017 Focus is a MK 3, not a MK4.