This is probably a common desire, being able to save a curve (in my case, from curveTubes) and call it back later to influence its initial geometry. Workarounds aren’t workflows, but I don’t know of either to be able to do this. Anyone come across ideas?
I realize that changing surrounding/underlying topology can mean it will often be easier to start with a new curve, but there may be a number of instances where it is far easier to work with something that has got you a good bit of the way to your final solution. Additionally, for purely aesthetic reasons as a mesh is further developed, you might just want to tweak a bit.