See the summary function of my ofn-path-edit script. If your spiral is approximated by circle arcs, you can also go back to the initial approximations, compute the length of each arc, and sum them.
Otherwise, yes, you can cut a path in sections. A bit harder than it looks if the path is made of several splines.
Otherwise, yes, you can cut a path in sections. A bit harder than it looks if the path is made of several splines.