The world border cannot be set to any value beyond 30 million.

This was strongly implied to be a possibility due to MC-187668 being resolved as a duplicate of MC-187664, which was later fixed in 21w17a. Despite said fixing, this remains an impossibility: while access beyond this point was heavily implied by these actions (making this probably not a feature request), it is not possible.

Steps to Reproduce:

1. Visit the world border using the following command:

   /execute in minecraft:overworld run tp @s 29999981.03 ~ ~ ~ ~
   

2. Attempt to set the world border beyond its default diameter:

   /worldborder set 60000001
   

   → The command fails because the maximum allowed value is clamped at 59,999,968 exactly

3. When near the world border, change the center value to your position:

   /worldborder center ~ ~
   

   → The command executes, but nothing changes and the world border stays at a maximum value of ~60 million.

Expected Behavior:

Due to the reasons detailed in the introductory paragraph, the terrain beyond the 30 million mark would be accessible via changing the world border.

Observed Result:

Anywhere beyond this region is still completely off-limits despite the given reasoning.