First Request:
Option to create a “tween curve” at a specified ratio of the distance from the first curve selected to the second curve selected.
Specifying a ratio between 0.0 and 1.0 would result in a curve between the two input curves. The smaller the ratio the closer to the first curve, the larger the ratio the closer to the second curve.
Second Request:
Option to create a “tween curve” through a selected point. This is essentially the first request but with the ratio defined by the location of the “through” point relative to the input curves.
The difficulty/complication/challenge with implementing this request is possibility that the selected point may not lie on a “tween curve”. In that situation the curve should pass through the point on a “tween curve” which is closest to the selected point
Agree. I usually create 10–20 or so tween curves, pick the one I need, and delete the rest.
Being able to specify the position/ratio directly would be a more polished approach, and would also reduce the potential for errors when working with a set of curves.
what do you need the exact ratio for? “through point” can be achieved with ExtractIsocurve. making a quick loft first is not a big extra effort and could be done with a macro for bulk work of that sort.