RE: U3415W, Display Manager for OS X?
Via the Mac Mini/ThunderBolt Port to the DP monitor port the resolutions I have offered are:
3440x1440, 2560x1080, 2048x858, 1920x804, 1720x720, 1600x670 60Hz/50Hz
Via HDMI I have:
1600x900, 1344x756, 1080p, 1080i, 720p (60Hz)
I don't think you are going to end up with the display options you want ie aspect ration 1.2:1 unless you get the option to set customisable display sizes in the Display Manager as this is not available on my Mac or PCs