Sorry for the slow reply, I've been talking to others in the office here
to try and work out what's best for this.

Unfortunately, even adding user-generated code would require extra
support.  We would need to assign someone to asses the changes and to
make the adjustments.  There isn't anyone currently available to take
that on, although it may be possible in the future.

But we do have a project planned for the near future that's going to
look again at forums for the whole of Wikia.  I'm very much hoping that
the result of that will be to give a much improved version that should
be a much better option than the current wiki pages or the phpBB forum.
 So I think the best option for now is to ask you to bear with us, and
wait for that project to get underway.  I'll ask that Runescape gets a
look at the ideas as soon as possible, so we can make sure it works for
your wiki.