Of course - that's how it's done! The Elite: Dangerous guys are geniuses!
From the proposed mechanics of the frame-shift drive in
this design document, while travelling at very high speeds through empty space: "It also alters the visuals from the cockpit significantly, for example other ships travelling at super-cruise are rendered as distorted flaring lights, visible way beyond normal visible range, and other astronomical effects, like magnetic fields become accentuated too, rendering them visible in many cases."
This is a great way to resolve one of the main limitations of realistically-sized systems, which is the fact that it makes random encounters between agents much more rare. But if you could
see NPCs at much, much further distances if you're both travelling in cruise mode and you can
reach NPCs in good time at the kind of velocities you're travelling at, it would be functionally equivalent to having smaller systems, shorter detection ranges and slower travel; you'd still get random encounters quite often this way.
For instance, if an NPC and I are travelling in cruise mode at, say, 1,000,000 km.s^-1 each, then if we make it so that we can detect other ships at 15,000,000 km ranges in this mode, all that needs to happen is for the NPC to come within 15,000,000 km of me or vice versa, and then it can detect me and, if it wants, start flying towards me and reach me in good time (perhaps a minute depending on the cosine similarity of our respective flight vectors?), and that would constitute a random encounter. 15,000,000 km might be too small given the scale involved, but in that case it could just be scaled up. It becomes a balancing issue.