The address allocations are not grouped geographically in the world today or in this scenario -- via some 3D space coordinates -- so you cannot get around this problem.

You don't know which direction any address is so you need a table holding every allocation and the next best hop for it.

When a company buys a huge allocation and resells it to customers they only have to announce that one huge allocation and they handle the rest internally.

When everyone gets an allocation they all have to be announced from wherever they may exist on the planet, or in space.