An update: the second guy showed up. As I expected, the file was not transmitted to him at all; he didn't even know there was a first guy. And the little amount of information the company had given him... was wrong.

Fortunately, this second guy was good - and, apparently, used to working with missing or incorrect information. He did all the needed tests to figure out the correct parameters. I served as his assistant to solve the biggest problem of my specific fiber installation... and against all odds, we succeeded. That was a pleasant surprise.

It is still not working, because the signal is too degraded between the OPC and the floor box, and he needs to find another line to use. But it was progress - much more progress than I expected. The dude left 4 hours after arriving (for a supposed intervention time of 45 minutes) and is coming back tomorrow to finish the installation. With a little luck, it will work tomorrow night.

It's the little ones, going above and beyond to do good work with zero help from their hierarchy. Remember them.