This is super useful, I probably wouldn't be able to troubleshoot any iron farms without it.
But could we please get options to turn certain things on and off? Even if it's just a text file. It's incredibly difficult to use when slime chunk borders are stuck on the screen, blocking what I'm trying to see. I tried just deleting SlimeChunkRenderer.class but that didn't seem to work.
Keep up the great work!
Edit: spoke before I read through a few pages of responses, didn't realize there was a config folder. (I don't typically use mods.) An in-game options menu would be nice though, and maybe some granular controls like custom color options per structure type, and more options on bounding boxes.
For example, a menu that had a button that lead to options for "Villages". When you clicked villages, you could choose if they're on or off, which colors they're "allowed" to choose randomly, and then options for each part (doors, golem spawns, sphere, etc) to have a filled or unfilled bounding box individually.
Again, keep up the great work!