Joining curves between different levels

I’m trying to connect the top landing of the lower level to the bottom landing of the upper level, but I am having some issues. Could I get some help on this?

The Vessel (32.1 KB)

For one thing, it looks like Join Curves failed:

I disabled some of your code and wrote this white group to create the zig-zag lines:

Vessel (39.6 KB)

P.S. The orange group creates half the connecting diagonals between layers. I’m tempted to cluster part of it that must be duplicated to make the other four. :thinking:

Vessel (55.3 KB)

P.P.S. I copy/pasted the code first to make sure it would work, then created a Diags cluster and used it twice.

Vessel (66.9 KB)

Internals of the Diags cluster:

I don’t know if you intend to use this “Master Form” vessel but maybe these polylines should be “pulled” to that curved surface somehow?

Or maybe not?