Let me start by saying that I haven't played apex in a month. I've gotten kind of bored with it. It took a a few games to get back into the rhythm. But after a while I started to do pretty good. I wasn't putting up 11+ kills as I did with my other settings. My sticky aim all but disappeared when using the apex as a Xim 4. But mouse movements felt a lot smoother. I mean really really smooth. Long range shots were a lot easier. Don't know why but I felt as if my tracking was a lot better and more precise. Pretty sure it's a placebo feeling though. I will most likely run my xim this way for a while.
Current Apex settings...
Xim 125 hz polling
Logitech G502 Proteus 4000 dpi and 1000 Hz polling
No SAB
No Boost
Curve set to 95 (leave yours on default I just prefer mine that way)
No steady aim
Hip/ADS 13/12.50
Default sync
And that's literally it. With this set up you can really run any dpi and polling honestly. This is just what I'm running right now per Od1n's tutorial for a Xim 4 feel. And I'm very impressed with how much you can do with simple settings. It goes to show that skill comes with time. It doesn't matter what settings you use. If you don't put in time you won't see results.