I'm not sure how it works with NPCs compared to players, but in any case it's worth noting that sensors do have an auto-resolve range which you simply can't hide inside. According to
this old (and therefore possibly outdated) post by Sandro, better sensors auto-resolve at around 500m. If that remains accurate and it also scales with engineering, current ships could potentially have sensors which auto-resolve out to almost 900m.
This is the best answer.
Most people forget, that they basically all the time fit just D-sensors and therefor have a complete difficult experience with Silent Running than NPC's.
A-grade sensors break through silent running at 500m and if long range mods really affect this too, it's even more.
You're not stealthy or undetectable in silent running, just harder to target. And yes,
my own experience tells me, that NPC's use eyeballing because they can hit you with weapons at 3km range even when using SR, just a bit less accurate.
The best is, not giving them the chance to get even one time a lock on you when using silent running. Keep from start on a minimum distance of 600m but better 1km.
They don't fire at you if they didn't completed the basic scan which takes around 5 seconds.
If they have a lock on you and make the scan, than the only way to break this scan is running away with ludicrous speed of opening fire on them. Than they stop. Firing is not recommanded by cops
