[Jeremy]

Hi Guys,

I completely understand the struggle.
I faced the same kind of problem in a tutorial I created, the canoe polishing.

I tried to do exactly what JF proposed, but I never found a way to make it work.

Seeing what you guys are trying to do, I would say that you absolutely need a solution.
One thing I would do in your situation is to look at the Inventor API and see how you can create a "Select Next Tangent Curve" and a "Select All Tangent Curve".
You certainly need to be someone that can write a few lines of code to do that.

Keep me posted if you ever find a working option.
Jeremy