Hey all,
building upon my first try on a "MultiPipe" implementation, I was looking for a way to implement the "true Catmull-Clark Subdivision (SubD) control cage" in MoI through pure Javascript, but found an easier way at the end.
The script is called MultiPipe2. You select a bunch of curves (a wireframe, a truss, whatever), run the command, and it comes back as one smooth, solid pipe frame with rounded joints wherever the struts meet.

How it works, in plain terms:
MoI already has a SubD importer built in. MultiPipe2 builds a simple, blocky "cage" out of your curves — basically a low-poly stand-in for the pipe frame, with a square ring running along each strut and a rough joint where struts meet. It writes that cage to a temp file, hands it to MoI's own SubD import, and MoI smooths it into a proper round solid. The temp file gets deleted right after, so nothing is left behind — it's just a translation step your document never sees.

It's roughly the same idea as Rhino's own MultiPipe command (been in Rhino since v7) — pick curves, get a smooth SubD pipe network out. Different engine under the hood since it's built for MoI, but same basic concept if you've used Rhino's version before.

A few things it does on top of the basics: it grows the joint automatically at tight angles so it doesn't fold through itself, it'll warn you about duplicate or crossing curves instead of silently ignoring them, and there's an optional "Round joints" mode that fixes pinching at heavily-grown or high-degree nodes (turns them into a clean "miter point" instead of a "dimple").

Script's page: MultiPipe2 README
Get it here: MultiPipe2.zip
README / how it works:
MultiPipe2 README

PS: Once again probing the capabilities of my MCP server - now it became my personal "J.A.R.V.I.S" ;)

Cheers,
Gabriel