this script works like select similar faces in polyboost or gmt, but with splines. so feel free to test it an post some suggestions :)
it have two modes:
by segments - selects by spline segments and their lengths (most precise)
by length - selects by overal length of the spline (useful in some cases)
new in v2.1
by type - selects by knot type (bezier,corner,etc)