Cool! Totally confirm my tests! :)
They are all tangent, centers are very near the Orange curve sometime up, sometime down...
Seems very sufficient for graphic drawing

And super the trick to use Flow for Bending something!

Now wait and see the little script or other trick for automate that! :)

In my opinion maybe more easy for the user to Put "first" and "last" circle with their own proportions sizes on the curve
even only the first one!

That gives the way of increase decrease...