So I had this idea for a very simplified setup for this kinda thing (link) but I ran into an issue very similar to what we solved for the "perfect tetrahedral tessellation".
The idea is to create a per primitive "box" and then (in a foreach) copy and reshape the object box to each primitive box, then use the new point positions to shift the copy object into place with a lattice. I tried to use the extract transform setup we used in the tetrahedron reshaping setup, but no luck. My brow is just to low to solve this it seems.
And yeah, it's kinda tricky to explain, hehe, but if you're wondering what the h*ll I'm drivelling on about, here's the setup.