I suppose there is a way to change the script of the object
but those add-on scripts are complicated and usually quite long.
Just out of curiosity, why do you place your section line
inside the wall rather than just outside of the wall ?
Looking at your image, it would seem that what
you want to show could be done by making
an elevation of the wall framing.
Then the only thing left to do is add a couple of lines
in walls that are not parallel to and cut by the section line.
It would be good, if you don't mind, to give us
a name to address you by.
Thanks,
Peter Devlin