Hi insekt,

re:
> Is there something similar to Sub-D Multipipe in Moi?

No, not currently.


> If not, is there a workaround to achieve the same result, with or without the Node Editor?

You might check out TopMod:
http://people.tamu.edu/~ergun/research/topology/download.html

If you export out from MoI into .obj format then bring that into TopMod I think it has some different kinds of framing methods for generating structures around polygon edges.

If it is able to build an all quad structure you could then export that back out to an .obj file and use the MOI sub-d converter (SubD > Create > "From file") to convert it into NURBS geometry in MoI.

- Michael