What i would love is to take a "team" of 10 cars with a IA pilot to do the dirty job in testing.
They would go all on indentical setup except on one parameter.
For exemple the ride higth. The ten cars have a value in a range I choose.
if it is 50 to 95 mm then the cars would have these values : 50 55 60 65 70 75 80 85 90 95.

They all start at the same place and time (with collision off) and then i see corner after corner witch behave best.

This way I would be able to try many options for a tenth of time. And then "finish" the setup myself the usual way.

What about drawing a line on the track. This line should be given by the center of gravity of your car during your best lap.
Plus a counter that show you in meters if you are late or in advance. (it could be a arrow green/red changing in lenght.)