Structure block bounding box visibility changes as you move around.

When using structure blocks the bounding box comes and goes. Sometimes you can see it and then you move a little and it is gone. This makes it very difficult to place multiple structure blocks at once. Also the color should be easier to see like chunk boarder when F3 G are pressed.

It would also be nice if you could select a color for the bounding box per structure block as this would aid in using multiple blocks.

Also a ghost image of what is loaded would be very nice to have for orientation use.