As this is not a problem report of specific flight, there is no debug attached

I have decided to move my flying in USA and get more practice on flying in to giant airports with a lot of runways and more complicated approach procedures.
Almost all the time I am flying with SID/STAR ticked on and it always works good in Europe, but I see that things in USA are slightly different. At first, STARs can be very long. Once I had my STAR started at 120 miles before airport.
But what I have noticed, that many airports, even having complicated STARs they still give vectoring to the finals at some point.
As for example flying to KJFK: At CAMRN expect radar vectors to final approach fix in use. If using STAR function, it begins at SIE VOR. I am cleared at this point to finals on pilots discretion, but obviously, not vectored at CAMRN. So it is just better not to use STAR function, include STAR in to flight plan and I will get vectors to any runway at CAMRN and that would be close to real world procedures I guess. Cool.
But here is another more complicated example, that I cannot figure out, how to make it closer to real world procedures.
Flying to KATL: I cannot modify flight plan to include STAR in to it and have closer waypoints, as I don't know which runway I will be assigned to land until reaching CHPPR and it is separate routing for each runway. So I still need to fly with STAR function on to get to the last point of assigned runway, but obviously PF3 will not give me vectors for the final at that point.
But I was wondering if there is some trick, to make such kind of approaches more realistic as it is described in charts? STAR plus vectoring to finals?
I thought it would be great to have a hot key function for switching between STAR and vectoring? That would make things easier and more realistic, simply hit the key when you reach the point where you should get vectors in real life

But I guess it is not that easy to implement, as it would be already done.
So I was just wondering, what would be the other way, to bring such a flight closer to real world procedures as per charts?
Or "cleared to finals on pilots discretion" is our limit in here?
Thanks in advance!
Viktor.