Well, worked out a ghetto way to set a world boarder.
Each overmap is 179x179. So starting one tile out from the first overmap (NW diagonal from coordinate 0,0,0) you would have to create barrier tiles 182 long on every side.
Start new world with character, activate debug menu, go to overmap editor and move cursor to 0, -1’179, -1’179 (NW diagonal from coordinate 0,0,0). Then you can run this autohotkey script and do something else for 10 minutes.
Top wall complete:
Loop, 182
{
Sleep, 100
Send, {t}
Sleep, 100
Send, {/}
Sleep, 100
Send, {r}
Sleep, 100
Send, {i}
Sleep, 100
Send, {f}
Sleep, 100
Send, {t}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 200
Send, {Right}
}
Loop, 182
{
Sleep, 100
Send, {t}
Sleep, 100
Send, {/}
Sleep, 100
Send, {r}
Sleep, 100
Send, {i}
Sleep, 100
Send, {f}
Sleep, 100
Send, {t}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 200
Send, {Down}
}
Loop, 182
{
Sleep, 100
Send, {t}
Sleep, 100
Send, {/}
Sleep, 100
Send, {r}
Sleep, 100
Send, {i}
Sleep, 100
Send, {f}
Sleep, 100
Send, {t}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 200
Send, {Left}
}
Loop, 182
{
Sleep, 100
Send, {t}
Sleep, 100
Send, {/}
Sleep, 100
Send, {r}
Sleep, 100
Send, {i}
Sleep, 100
Send, {f}
Sleep, 100
Send, {t}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 100
Send, {Enter}
Sleep, 200
Send, {Up}
}