All worlds have borders /wild and al its subworlds have the border at 1.5 mil blocks And for /waste and its subworlds have it at like 10k blocks or something like that(don't remember exactly) (small number)
The waste definitely isn't, but it gets reset every once in a while, and the wild's world border might get extended in the future, but in the at least 3,000,000 square blocks per server there's still more than enough empty space for many thousands of people to settle.
