Caesar automatically assigns a node number to the midpoint of the bend, and usually that's N-1. I do not know offhand what it selects if that node is already used - presumably next available one.

If you manually assign one, then it'll use that, instead. You'd then attach to that.

https://blog.hexagonppm.com/caesar-ii-webinar-modeling-and-evaluating-bends-with-attachments/