This is for paths within 3DGS only and as far as i know you can't change the number of nodes/edges of these paths at runtime.
It's also not possible to create circles/loops with these paths.

For all this I've made the more flexible "flex-path-system":
http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=250177#Post250177