I really like the Edit Mode. I run on PC and laptop with screen of difference resolution. So I tailor the base UI to make the most of the respective displays. So far so good.
However multiple chars have issues with the Buff Frame. It wants to skip back up the screen, perhaps to the default position after applying a Layout. Reapplying the Layout changes nothing; the Buff Frame stays where it is. You can go back into Edit Mode, move the Buff Frame to where you want it, Save and exit Edit Mode. And a couple seconds later ping, the Buff Frame is back in the position it likes, not where you want it. 
Small problem, but there it is. Incidentally, and anticipating comments, I have tried without any addons and I have tried installing addons to move and/or lock UI elements. However, I will take suggestions if people have employed a particular addon and found this “feature” stops happening.