I have tested this mod with Mineclonia and can not recommend it.
This mod limits you to the spawn chunk, to increase difficulty.
This seemed true at first glance. The movement blocking felt a bit too jerky though.
It also builds a nice obsidian marker around your 16-by-16 area of freedom (that you cannot mine).
When I entered a new world with this mod, I found no obsidian marker, but a bunch of server errors showed up during map generation.
The second time I entered that world, I did find an obsidian border. I assume that the placement code should wait until mapgen is done.
It works by constraining your position within the chunk, and disallowing any mining and building outside the chunk.
Mined nodes outside the spawn chunk are immediately restored, but since the nodes drop as items, this means that players have an infinite supply of everything that they can mine, which makes resource gathering absurdly easy. It is also trivial to move outside of the chunk with a boat, to explore the world and gather literally limitless resources; upon exiting the boat, the player is teleported back to the spawn chunk.
Yesterday I finished playing this mod and also found the bug with the boat. Maybe it was possible to go to the nether using this boat and then to the end, but the chances of finding the required fortresses within your spawn chunk would be very slim. I died when teleporting to the nether.
A more gamebreaking bug is when you exit to main menu when inside the boat and then reload the world, the 16-by-16 area resets to where you are, making it possible to go everywhere in a painstaking way.