Ok, so, I built this really cool house in singleplayer, and I want to build it in Vincent. I found a mod called schematica which, if you have a schematic, it overlays "ghost" blocks so you know where to place the blocks, and you don't need to do a split/dual screen thing with screenshots. This, I'm going to assume is fine. It has a feature called "printer" which, assuming you have all the items in your inventory, it places them for you. Is this okay to use? It does some weird block placing behind you thing when I tested it on a singleplayer world, which could be seen as cheating/hacking.
i would say that using the printing feature would be hacking/cheating because you are not doing it your self like vanilla should be but that is my opinion
It's OK if you use it to build things that you've built, though it's preferred if you did it by hand (with a ghost).
The printer feature is usually disabled server-side, I don't know whether by default or if a config file must be edited. The ghost version of the build is usually really helpful when building with other people so that they know exactly what to do, avoiding confusion and such.