Instead of 'super glue', try epoxy. You can get it inside the threads
under the nut AND get a big enough glob on the end that you could smooth it
out and even paint it to match the woodwork.

After hacksawing your threaded rod, look carefully at the thread where you
cut. You may need to file it slightly to present an 'entry' for the nut.

Other option: you could embed the threaded rod inside the wooden post, if
you envision this more or less as permanent. Drill a couple inches deep
and epoxy it there.