Why is there a forced stealth section?

[Typhoria]

I've seen someone do the same thing you did. But it wasn't the NPCs aggroing them, it was the one closest to the end door seeing him, since there's not really much of a "safe" spot by the door out of LoS of the one that paths there. It was quite obvious watching it, too. You aggro one, you aggro them all.

That certainly is possible, just not intuitive. Typically mobs, for those types of events/puzzles, only have linear vision, not arcing.

[Hezzlocks]

That certainly is possible, just not intuitive. Typically mobs, for those types of events/puzzles, only have linear vision, not arcing.

I understand what you're saying, but I saw no reason for it to be any different from how mob vision usually works in this game as is, where, assuming they are identical in level to you, if you're behind them you can often go right up to them without being seen, but if you're anywhere in the approximately 180 degree radius in front of them they have a large detection range. Given the linear nature of these pathways, it achieves the same general outcome as having linear vision, barring that one spot by the door.

The real question is, how does their sight work while you're in those small hidey holes? I pressed up against a wall to minimise detection risk when I did it, but it's entirely possible that if you just stood in the middle of these hidey holes, or against the opposite wall, they would see you there, too.

In any case, I don't know what happens if you aggroed both of the stealth rooms, but the one room I did see get aggroed just resulted in an easy fight against them, no instant fail state or anything. If this is true for both rooms, I really do not consider this a "forced" stealth segment at all. A true forced stealth segment is one that instantly fails you for being detected, and is the bane of many games. This one here seems entirely harmless and is just a nice change of pace.