I have an 03 Cobra which I autoX about 10 times per year. My 03 is considerably more nose heavy than your 01 due to extra weight of cast iron block & supercharger. On the IRS I stick with the factory recommended -.8 degrees Camber on the IRS because with my more nose heavy car more negative camber out back would give it more bite in the rear & increase the tendency to push (understeer) in corners. I set the Toe on the IRS to as close to Zero as possible. However with your less nose heavy setup, you may well be able to take advantage of more negative camber in your IRS.
One non-alignment consideration you may need to address is unpredictable bump steer in the IRS which can cause the rear end to kick out unexpectedly in cornering situations. You don't want the rear end steering the car. This can vary from car to car due to production tolerances in the IRS.
When the IRS in my 03 Cobra still had the stock rubber control arm bushings & stock toe links which were not adjustable for bump steer, I had this problem with my Cobra. In a normal street driving situation, I took a 45 degree corner at 45 mph on flat, dry, clean pavement in excellent condition, I was not accelerating & the rear end kicked out! My Prius could have easily handled that without any problem.
Hopefully you will not have the bump steer issue, but if you do, here is what I did to address it: In installed the FTBR IRS upgrade kit which replaced all of the rubber bushings in the IRS with Delrin bushings which have no give (stiffer than polyurethane) & I replaced the toe links which are bump steer adjustable with shims at both the inner & outer ends. With this upgrade the bump steer issue was eliminated. The car became completely predictable in cornering situations & responded precisely & immediately to any steering inputs. I would recommend you get your alignment, then autoX it and see if cornering performance is predictable and the car goes where you point it. If good, no IRS upgrade required. If not good then read the Tech Info on Bump Steer on Maximum Motorsports website which explains the process for correcting it. A normal alignment shop cannot do this. You must use a Bump Steer Gauge to measure the toe changes which cause bump steer & figure out what shimming needs to be done to minimize bump steer.