I get it that you want swipe. I have no idea whether CM12 actually supports it or not but I'm 99% sure CM12 supports dt2w, which is almost the same thing.But swap doesnt work for cm12 and again: I need swap!
All I'm saying is that your only 2 realistic options are:
1. stay on stock KitKat and enjoy s2w
or
2. settle with dt2w on CM12 and get tons of cool CM-features and Android L, which is as good as your M4 will get.
CM11 is not an option because you will get *a lot* of problems with practically every function of your phone. It never worked, and it never will.
It's called making a compromise (-: So decide for yourself what is more important to you: s2w or new Android with dt2w.
Sent from my OnePlus 2 using Tapatalk