Actually, the OP is trying to edit his map and he doesn't want to build a Yew tree tile by tile so he was looking for a quick way to put these giant trees in the world. He has no intent on moving them once his world map is built. Also, it is better just to have your map as complete as you can get it and reduce the server's item count by not having them consumed with plates, forks, cups...like RunUO would do when you "decorate" the world. If players are not going to interact with the objects, they might as well be in the map file. There is an annoyance factor when people just decorate the world in game and set things to unmovable...only to run into an area, press CNTRL-SHIFT, and have a ton of item name bubbles pop up and flood your screen.
The distribution of new map files isn't a big deal because most people that run a shard have an amount of players they can count on their fingers. There are even some programs that can auto patch for your players but having them download a zip file of replacement files isn't that big of a deal either.