I would
expect to see uneven pad deposits when running the OEM pads or Ferodo DS2500 on the front of the car. Those pads are not designed for road course use on the front of a heavy, fast car! You need the proper tools for the job, which are racing/track pads with a higher max operating temperature. You will melt and smear a street pad on the discs when you run them up past their max operating temp.
The most popular combination among our big brake kit customers is to use Ferodo DS2500 for sport driving, mated to Ferodo DS1.11 (moderate mu) or DSUNO (higher mu) for track use. The great thing about this combo is that both compounds are made from the same core materials. As such, you don't need to completely re-bed your discs every time you go from street to track and back. Not only do they work well in their respective environments, they make the whole experience a lot less labor-intensive.
Ferodo DS2500 for the Front M2 OEM Calipers
Ferodo DS1.11 for the Front M2 OEM Calipers
Ferodo DSUNO for the Front M2 OEM Calipers
Ferodo DS2500 for the Rear M2 OEM Calipers
Ferodo DS1.11 for the Rear M2 OEM Calipers
Ferodo DSUNO for the Rear M2 OEM Calipers
When running pads from different manufacturers, you really need to carefully manage your pads and discs to avoid judder/vibration. In the video below I demonstrate how to do so. One never knows how two different materials will 'play' on the disc face. Sometimes they interact okay, but other times they make a total mess!
How to Between Street and Track Pads: