Maybe it's allready in the navroute commands, dunno, haven't used them yet, so sorry if it is, but what about a button in the routeplanner to automaticly plot the same course in reverse. You know, for those 8 jump missions where you wanna avoid storms.

plot out your course and save it as a navroute using /navroute save "name"

you can either plot a course to, and a course back, or do it all as one bulk course.

then set up the following alias

/alias nload "prompt '/navroute load' "

and bind it using
/bind <key> nload

then all you will have to do is press whatever key you specify and type in the name of the navroute.