Can be for many cases, but im asking specifically for manaroo.

Lets say miranda moves and from experience both players know its range 3 or just inside range 2, and the player takes a lock on manaroo without measuring.

Now, I can legally "verify" it is in range, but what I want to do is check if a nearby ship (lets say its behind manaroo) is out of range that manaroo can pass a lock too.

How do I go about this legally? Do I measure from Miranda to manaroo, extending the ruler passed manaroo easily seeing if the nearby ship is in range? Or measure from manaroo passed miranda, and eyeball the extra distance compared to my nearby ship?

Hope that makes sense. This is in the same category as checking a lock even though its clearly out of range to measure a boost, etc.

I just dont want to ruffle any feathers in the way I go about it.

This is actually in the rules. When checking for a target lock, you place the '1' end at the ship which is taking the action and see how far along the ruler the other ship is.

In this case, because you are verifying the range for your opponent's action, you start at their ship.

I would be very explicit about why you're checking something, including the bonus information that you are trying to obtain so they get the same extra info. And maybe ask them to do the measuring since they are the one who is supposed to be doing it? And if their hand happens to be obscuring what you're after, that's tough.

Be honest, be polite and if you don't get the info you want, don't whine?

If you are talking about Miranda using Long Range Scanners to target lock, your opponent can simply use a range 2 ruler (plenty of those FFG official ones out there and even if unavailable, a 5 straight template will suffice) to show that the target lock action is valid.

That limits gleaning any additional information about a ship that is behind the intended target.

You can ask to verify validity but you probably cannot insist on using a full ruler for the verification.