Join polylines efficiently

Eight posts into this thread and you still need this? :man_facepalming: READ IT!

3. Attach minimal versions of all the relevant files

How can you expect an answer otherwise?

In this case, a GH file with the three curves internalized would be a minimum requirement. The mesh they were created from might also come in handy.

P.S. On second thought, I see that you have created four threads here so far, none of them with a GH file posted, despite being asked repeatedly. Ignore that convention and you will be ignored.