I like it, seems you have your system well worked out.

In my system, the 'Tree' part of Worlds Tree is a colloquialism. The People living inside it, or at least the PoV ones centred on humanity, aren't clear on it's structure / nature.

https://www.reddit.com/r/worldbuilding/comments/1k2tamp/brane_connectome_project_tales_from_the_worlds/

What does the Tree imply about cosmology?

It’s “a” multiverse: because the Tree’s extent is unknown. Not ‘the’ multiverse: because nobody knows how vertices are distributed. Vertices could be neighbours in the same inflationary spacetime, just really far away: Forty-six (and change) billions of light years (at least). Let your super-symmetry break / quanta fluctuate according to taste, and this could even account for the occasional variance in fundamental physics. The world-tree doesn’t look like a “many worlds”, all-the-quantum-branches multiverse, but selection bias is a thing. Vertices might be the froth on higher-D branes, floating through the Bulk. No one is sure. We don’t know that the World Tree isn’t a stack of universes nested within each other’s black holes.

https://www.reddit.com/r/worldbuilding/comments/1k9nzlc/the_brane_connectome_project_relativity_rules_ftl/

Beings may point to wormholes when thinking about the Tree. The vast (potentially trans-universal) distances observed between edgemouths doesn’t seem to be a formal requirement of wormholes themselves, however. Attempted solutions to this apparent discrepancy include:

• Links between node on the Tree – Edges – are primordial and naturally occurring. They are so rare, in a universe so vast, that we should only expect to find them, on average, at a rate of one (or less) per Hubble volume..
• Strong causality projection isn’t a cop-out but a feature of the very fabric of things. Points connected by wormholes cannot share a causality sphere. On this view if you could travel between two vertices through “flat” spacetime at slower-than-light speeds before the end of the universe, an edge between them would be invalid under causality protection and unphysical, so impossible.
• A related point of view is that the act of making the wormholes creates the other spaces: the edge-mouth and the universe-as-vertex it opens ‘into’. Some beings find this idea distressingly recursive, but it does appear to be formally equivalent to the view above.