Offset curve fully grafts tree structure?

Dear All,
Looking to resolve an issue with with the script I’m recreating from the following YouTube tutorial:

(the preceding tutorial to lay out the panels on the plane is here:
I got to the point (2:50) where they have offset the sides of each triangle and now
going to select the end points of each offset curve. For that they understandably
get the three List Items with corresponding indexes 0, 1, 2 - for three offset lines in each of the 50 triangles. For some reason in my script List Item is not able to pick each of the three points when i input a correswponding index (0, 1, or 2). With each of these indexes the list Item picks all the offset curved at once (as shown on the clip below). It looks like after the Offset component the tree structure for some reason got changed and every offset line was put on a separate branch with index 0 (150 total branches), as opposed to preserving 50 branches with 3 lines (each triangle) in each.
Could someone, please, look at the video and my attached scripts and snapshot and see why my script does not repeat the behavior in the Tutorial?
Many thanks for all the suggestions!

11_offset and (40.0 KB)
09_orient_v6.3dm (62.3 KB)