Hey just wanted to share a solution I came up with for hiding the all of the device zones at once, in case anyone sees my previous comment.
Since I keep all of my devices in one folder in my outliner, I can just click the little eye button next to the folder in the outliner and toggle visibility for all devices at once. This is more convenient than clicking the eye for each individual device. Also, I just realized that if I hide the static mesh for a device in the outliner the colored zone box is hidden, but the neon outline remains, which could be a useful effect if you want to see the zones but you don’t want them to be as visually prominent.
I still think it would be nice if G toggled the device zones though, because then I could toggle them at the same time as the other gizmos/icons. And some creators may not choose to keep all their devices in an easily hideable folder like I do.
I made a post with this tip. https://forums.unrealengine.com/t/beginner-tip-hide-the-device-zone-boxes-in-uefn-editor-view/724262