Spawning Spheres - MC-Machinations/PaperTweaks GitHub Wiki
Allows you to view the spawnable area around a center point through the use of glowing spheres. Useful for proofing farms.
Commands
/spawnsphere|ss add <RED|BLUE|GREEN> - Adds the specified color sphere. Can only have 1 sphere of a color at a time
/spawnsphere|ss remove <RED|BLUE|GREEN> - Removes the specified color sphere.