This is going to be a meaty one.
HN2's stealth suffers from a rather large problem - it's too easy to escape a chase. As such, stealthing becomes rather inconsequential due to how easy it is to avoid AIs by simply running in circles. This is primarily due to the AI's lack of defensive measures against the player, as well as the AI's strange freezing behavior, and the unfriendly level designs.
This is a change that would require essentially a large rework of both the level design and AI, things I've already talked about in previous posts - but I bring it up again because it's NEEDED in order to improve the stealth-focused gameplay. Better house layouts with more choke points and shortcuts, AI traps and defensive actions, the works.
As it stands, HN2 isn't a game about outsmarting an AI, it's a game about running in circles until the AI looses track of you. It works in the off chance, but its flawed to its core, and needs to be worked on.