I don't know the definition of tree miller...
[EDIT: as the video I linked to disappeared, thank Robotnik for pointing this out]
But there are a variety of semi-automated tree harvesters out there that are capable of a modest amount of AFK.
The idea is for you to have saplings in your hand, plant one, have a bone meal dispsenser adjacent, which bone meals the sapling.
Once the sapling grows into a tree, a large redstone device, which surrounds a 5x5 area pushes the logs out to a large wood collection area.
If you are daring, you can build an enclosure for a wither, and have the wither blow up the wood, most of which will get harvested.
Saplings are collected in hoppers at the bottom, and moved back to you, so you just have to sit and plant saplings.
There are many tutorials on the topics, in particular, google: Minecraft automatic tree farm (or minecraft AFK tree farm). A video from a more famous youtuber than previously posted is here:
I'm assuming you run the server. You could:
- Op yourself and disable spawn protection, then mine out the area.
- Use a plugin to set the spawn point (I'd suggest EssentialsSpawn)
- Load the map into MCEdit and move the spawn point up a couple of blocks.
If you don't run the server, see if you can set yourself a /home position.
Best Answer
I think I may have found a solution for what you are asking. I went into the world creation menu and changed the World Type to Superflat. From there, click Customize below it and then click the Presets button and select Tunnelers dream. This gives one layer of grass blocks, followed by 5 layers of dirt, then 230 layers of stone, and finally one layer of bedrock. Since this is superflat it would generate a completely flat top but it does give you a looooot more under ground to work with. Heres a screenshot of the layer settings I mentioned to give visual aid.