how you it test? ewar?
Only active modules may cause the NPC to follow you, for example ewar
if you stop acting against the NPC, they have released very soon.

DEV Zoom - check for the NPC code for the line:

if (target == Ville)
{
   follow forever
}

i couldn't even reproduce red NPCs "following forever" on gamma. They always went back to their group, once i got a certain distance between them and my robot...

This makes sense now:

This is why BadAss was able to lure NPCs aware from Chemist and hold them on alpha.

I thought the entire reason why NPCs were created was so that mission mobs would not wander away from their spawn for missions?  I know with a mission patch at hand that would be cool, but its quite annoying and would solve a lot of headaches for mission runners if.

Orange NPCs disengaged after 15 seconds of inactivity from the attacker.  I don't know when this feature changed, but it needs to go back to that.

No I just had a few missions where I needed to chasis scan something and all I did was scan it unlock it then move back to the station.  I go about 80kph so the orange npc follows me because I don't out run it.

So I guess it's in the 'Agro range' and can't increase distance because it's too fast?

Orange NPCs only follow you if your robot does something that keeps refreshing aggro. If that something stops, they disengage after a short while (15 secs I think).

Something that generates aggro, like active offensive modules or locking. Moving does not generate aggro.

Ok so if you have a longer lock range and you lock  a npc and it doesn't lock you it will follow you until it locks you as long as it still sees you.