I stretched my coil out into more of a wide ribbon and just let it float in my XSPC res/top on top of an MCP355. I haven't yet seen it get sucked in on its own volition, the only time it got close was when I was tinkering with the reservoir, but it still didn't get sucked in or hit the impeller or anything.
I tried finding a picture, but I don't have one specifically and don't have time to upload it, sorry. Either way, I haven't had a problem, and I hear a lot of positive feedback from people about just screwing it as a coil into the tubing before or after a fitting and it never moving. I posted a thread about this when I was building my setup, and nobody seemed to have any problems in any of the settings of placing it, so you should be good to go regardless of what you do with it.