I haven't been able to get USB 3 to work and I'm not sure it can work at least not on High Sierra. So far, I have yet to encounter anyone on this forum who has managed to get a fully working High Sierra System on the ASUS x79 mobos, especially with the Asmedia USB 3.0 1042. If you're one of those lucky few, but still have sleep issues, I can almost certainly say it's due this particular device. I cannot, however, confirm it with any certainty without enough data to work with. It's why I am asking for some configuration information.
I've read some of the ACPI specifications (1000 pages long), I've learned that USB is extremely critical to sleep and its interface to the power management system is very complex and tightly integrated. It's why you can wake up a machine by simply moving a mouse or pressing a key. The other onboard Intel USB works flawlessly primarily because Intel couldn't afford to have a bad implementation of their own specification.
If I cannot find a solution, I can at least help confirm what the source of the problem is.