Looking at the first vid, some thoughts..
I'm assuming it's an Attack-type volume as it is pitch black and everything seems to know where you are (you are getting GPS-tracked by the wights, first one hits the diagonal wall instead of you, second one lands a hit). It could be the new trigger type as well (3), I haven't tested how those work exactly. But assuming type two:
You reveal yourself at 15 secs in, to gain some speed I presume. From that point on, everything that sees you is following the normal agro rules. So, if you were to enter stealth at 16 secs in, right in the middle of that room, the zeds should likely lose you already. This is based on A20, so reality might differ. IF you're going back in, give it a whirl.
Then again, you're in god mode.. based on the audio you took two hits, bleeding from one. Not a horrible fate yet, but you could've gotten stunned which would've ended the escape. And the god mode does reduce your "crit taken" -chance for secondary hits.
And if you DON'T do the self-reveal (as in you stay in stealth the whole maneuver), the zeds that haven't "properly" seen you, won't reset as easily as the rest - which is quite counter-intuitive.
If you're still in testing it, try dropping in, leaving stealth in the middle of the room toggling headlight on&off, then re-stealthing in the middle of the room. Having LoS to everything, but the darkness should save you.