You've gone through it to Rin's room? I haven't even done that yet. That must be the mansion's coordinates since it's the only one I have left to do. As for the flesh wall nightmare... Your hint is in the logs on the console behind the black suit.
I've been re-rolling Jessica transformations so much because of the mimic chest rng. I think I'm onto a pattern... Let me know if you notice this as well while you play. Purple eyes seems to be a relatively short timer, magenta seems to last about twice as long, but red seems to just refuse to go away, while grey eye Jessica seems to only show her face once but the timer is like the red eyed variant.