Our network had Power Settings enabled and about 300 computers STILL try to "Wake-Up" at 5:30 every day - AFTER we removed the power policy. If we enable ONLY the setting to disable wake-timers with no other option set will it effictively fix this, and also NOT overwrite other settings our users are already set to locally on the computer? we dont want to enable this and have them start sleeping during the day again.

Create a custom client setting with a high prio and apply it to a collection containing a single test computer. See what will happen.