There should be a way to select and move multiple decorations at once, or a way to group them together to accomplish the same thing.
A bit of background: I'm part of a small Ghost Clan of close friends, so we don't have a super fancy dojo. I was inspired by the winners of the dojo contest a few months back to make something cool for our dojo. It was the first time I tried to build anything large scale, partially because doing so was difficult before the dojo revamp. So I built a small floating island out of Lua pieces, and was pretty happy with it, until I funded parts of it and realized that the pieces weren't being lit well by the lighting system where I had placed them. I was faced with two options: either manually move the pieces one by one or start over. This is when I realized that there is still a limitation with the new decoration placement system: there is no way to mass-move decorations or otherwise "group" them all together. As a result, I elected to use the former approach to move my island, which took me an hour of my time and made me really wish this feature was in the game.
Think of it like how you would select multiple files in an operating system to move them, or selecting multiple objects in a 3D modeling program, you could hold down a key to "shift" or "ctrl" select multiple decorations. Then you could either group them together to move them as if they were one object or simply mass-move them all together. This would make managing large builds in the dojo much easier, and allow for more freedom in where you place them. If a clan decided that they wanted to move one of their fancy builds, they would be faced with the same conundrum that I had (only probably worse since some of those winning builds were insane), and this is a simple solution to that problem.