Don't need beacon sats I think, should be able to shoot position with radio/light noisy regular variable stars.
https://en.wikipedia.org/wiki/Cepheid_variable
Their regular transmissions have been going all along, require no setup and would be measured as a matter of course from each new system.
I suspect one could get a precise clock time out of them as well, another key tool in navigation.
Sure, not needed, but probably convenient as it easies it.
What you tell about is probably what scouts use, but, even if not needed, those beacons are useful for comercial ships, probably more used to "civilized" space with this kind of facilities.