Is there a controller setup that can make it feel more like GT Sport?
There's a few things you could do to make the cars feel more weighty/dull/less twitchy, I'll explain & advise but leave it down to you to decide.
Baring in mind I haven't played GTS so I can only go by what I remember GT5/6 feeling like.
1. FOV, surprisingly this also adds weight to the controller as you increase it, default PC2 is 70, I have it at 75. You could start at 85 if you wish & adjust your seat position accordingly afterwards. Anything over 90 does create the fish bowl effect, also this could effect your judgment of braking distances & corner apex.
2. Speed sensitivity, this stiffens up the steering sensitivity as you go faster, default was 67 I think, again I have mine set to 75. Again you could start at 85. Anything over 90 means you'll have to be at the perfect speed for that corner, anything under 90 will start to introduce a more higher steering ratio, meaning you could over steer the car, (not the same as the car having oversteer).
3. Controller damping, stiffens up the controller input across the whole range making the steering feel more sluggish regarding turning left to right. Personally I hate this & have it on 0 (I used to use 75). If however you require this take note that if you go too far above 75 (magic number) you’ll find it hard to catch slides/oversteer & flick your car through tight left/right chicanes (like at Monza). Start at 85 again if you wish. (definitely not a good idea to have this too high regarding rallycross)
Steering dead zones leave at 0 unless you have drift stick on your controller & steering sensitivity leave at 50 as this is 1:1 with your controller inputs (as with acceleration & braking).
My personal settings are
0
50
0
50
0
50
0
100 (instant clutch, although set to auto)
75 (speed sensitivity, slightly adjustable)
0 (controller damping, I never touch this)
75
0
I only adjust speed sensitivity up or down slightly regarding what car category I'm driving, car's with high grip/downforce (GT/LMP etc) I raise it slightly. Cars that require a little more slip (vintage/rallycross etc) I lower it slightly. But in general it stays around 75.