Hi Mike,

> Tried it out and the loop script seems to only work if the
> associated (looped) curve sections reside on a shared plane.
>
> Perhaps the loops that are not being selected for me with this
> script have some sort of planar discontinuity to them.

The way that script works is that it targets the trimming boundary of a face for selection - it doesn't particularly matter if they are all planar or not, it's whether all the edges belong to one common face whether that particular face is curved or planar.

But joined edges belong to 2 faces so to identify which one you want to follow you need to select 2 consecutive initial edges on the loop that you want to select, that makes it able to identify which one it is supposed to follow - see the above links for some more explanation.

In the future I do want to work on some additional chain selection methods as well.

- Michael