Exactly. I have that issue at work; nothing at all to do with this topic, but still the same. We have to do things like install cue lights in the set for a production, set up mobile video monitors with the conductor visible on them, maybe an audio monitor.
It's all well and good when you have just been through the final phase of the rehearsal process. You've been there as it developes, and know where and why it all has to be.
The thing is, a production in an Opera house like the one I work in can go into storage for a couple of years, and then be brought back into the repertoire again. And then you look at the documentation, lists, photos and so on, and ask yourself "Häää?". Where exactly is that, and what exactly is its purpose?
Good photos and precise documentation are the Alpha and Omega, and everything in between, and a bit more on top.