So let me just start by saying that I love how easy it is to make something visible on only certain devices within the Webflow designer… no need to make extra utility classes for that stuff… awesome.
One thing that I think needs some attention is seeing those select items in the design view. It's easy to forget that you made a certain div or whatever only visible on "X" device. I don't know what the best solution is but a simple one I can think of is keeping the elements visible in the designer at all times with maybe a red outline or some sort of visual cue telling you that this item has specific display settings applied to it.
I hope this makes sense and I'd love to hear others thoughts on this.