This is the most sensible aproach that I have seen yet.
For cornering characteristics, see if you can find a carpark that is empty on Sundays, or some other large patch of pavement or concrete. I know it is a bit hard these days, but have a look around anyway.

Next, with a friend & a rope, mark out a 30m circle, or some other diameter that you like and can repeat.
Next, drive around the circle at a steadily increasing speed. It might be a good idea to have a friend behind you to watch the oil pressure and speed, and nothing else, particularly if you think that you can generate close to one G of lateral force.
This is a repeatable test and will show up some interesting traits with diferent tyres and suspension changes. Oversteer or understeer should show up nicely too.