Not really, maybe I've explained poorly.
They say a picture is worth a thousand words, maybe the rubbish I can draw in paint is worth a hundred.
https://i.ibb.co/dr17dHx/Untitled.png
It's a pretty terrible picture, but I hope it serves to get across the general idea. The slice is for visual effect, not because I think the tip of the tower was actually physically used like a knife on a birthday cake. :p
It's one unit, one "timeline" if you like, just split various different ways at various points.
It's not about having space as in an actual physical space for it to go, I mean space in the sense that Etheirys is an aether rich place but the worlds contained within only require 1/14th of the total resources, and there are currently far fewer than 14 worlds.
G'raha's "original world" starts as the Source, and I personally think it probably has to be the Source, I doubt the Shards are meaty enough to survive being sliced any thinner, but his adventure doesn't require that said world
ends as the Source. All that is required for his trip to work is that his original world and the events that led to his departure are preserved.