It's not meaningless to me at all, as I have always made a point of signing the guest book in systems I pass through whenever possible and there's a great number of such systems in certain areas, like around Bernard's Loop, the Colonia Highway, or other frequented places. Anyone could simply toggle it off when you do cross that threshold, like can be done for the other default options (which I most often keep turned off).
It's not so very straightforward that I could do it. I looked at the documentation you have and I didn't spot the necessary variable to add or a step by step guide to how to set up the custom file correctly - rather, doesn't your own documentation state it's simple
if you are accustomed to programming?
I'm curious how the game client knows about footfalls or why Fdev haven't seen fit to include that in the journal...oh well, I guess.