Is there any dedicated function that would unload then load all the chunks or i would have to go through all the chunks in range (defaults to 10)? And the other way around, how could i detect which chunks are loaded by the player and which are not for resending the "fake blocks" when the original ones load again automatically (due to player moving out and back in)? Context: specific players see a "layer of fake blocks" which others cannot. If they leave the group, blocks should go. When they join a group, blocks should appear. This happens currently but after exiting fake blocks will remain hanging around and when joining/moving in and out of range they won't reappear again. I have ideas about this being a separate empty world containing all the block changes then combining it (is it possible to override the normal chunk loading procedure?), just storing the edited blocks, i dont know the adequate solution.