Is there anyone who knows a way to prevent from 173 from actually "seeing you"?
For example instead of coming straight for you not knowing where you are in plain sight (like 106).
And also if he cannot see you does he go for where you were last and try to find you there? or does he automatically know where you are?

He always tries to get you, even trought walls (he always knows where you are), but when he fails, or glitches inside wall, or in central rooms (like server room) he has pathfinding points he must use. That's why he can not get you in corner of server room. He's not allowed to get there. Normally, in other places, he just comes straight at you.

He uses an S-NAV Ultimate when you're not looking.