I agree with exeng, with one proviso. Keeping other waypoints on the FMC can assist with situational awareness. Distance off the centreline is not particularly helpful, except once you've intercepted the localiser, to work out how awful your approach is!
In other words, what is the point of knowing that you're 10 miles off the centreline, if there's a mountain you can't see between you and the centrefix which you're being vectored around?