I used the Geforce Experience app to customize the resolution and
Skrim SE Surround mod to fix the UI / HUD / GUI (whatever)
The mod is not available in the game's built in mod library. You have to copy the files directly into the Data folder.
IMPORTANT:
If you want the UI in the center instead of on the sides, make a file called SkyrimCustom.ini in c:\users\_yourusername_\Documents\My Games\Skyrim Special Edition\ and copy paste the following:
[Interface]
fSafeZoneX=250.0
fSafeZoneXWide=1300.0
fInventory3DBoundRadiusScale = 8
fInventory3DItemPosXWide = -21
fInventory3DItemPosYWide = -900
fMagic3DItemPosScaleWide = 0.8
fMagic3DItemPosXWide = -14
fMagic3DItemPosYWide = -600
fUIMistMenu_DefaultLogoNIFScale = 0.3
fUIAltLogoModel_TranslateX_G = -25
fInventoryLightRadius = 1200
fPlayerBodyEditDistance = 350
fPlayerFaceEditDistance = 200
This is for 5760x1080 and can be tweaked if you have bezel correction or something, but much easier to just leave it off. Now you don't have to break your neck and you have full UI in Skyrim SE.