I presented some ways to select area where quarry works, such as Maker Plus, Flexible Marker and Chunk Marker.

• Maker Plus is like markers in Build Craft. Place 3 marker to create a rectangle and right click one of them to select area. It's, in my opinion, stressful to adjust the height or coordinate as the marker requires others to be on the same x, y or z.
• Flexible Marker can enable you to select area on GUI, click +/- to expand area. It's more useful than normal marker but you may have to repeat small changes to select area you want to dig.
• Chunk Marker is a good choice if you want to select 1x1, 3x3, 5x5 chunks of area. But is it a bit rough?

Let's give another way, like Building Gadgets. It's a popular mod to support building in some ways. One of its great points is the rendering. It will show you concept of filling/copying/etc. before the works is done.

The key concept is to visualize the selected area. I noted some reference to insert render of area.

1. Render Event and item filter
2. Block Renderer
   You can use NBT tag to send data from server world.

This is my plan, so I'll implement when I'm free.

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