10 degrees sounds like a lot of roll, especially for a single seater, but i don't have any real feel for the figures in this case. When i've tested FRenault before it's always been limited to pitch & ride height mapping at best due to budgetary contraints, so no yaw, roll or steer effects unfortunately.
One thing to watch out for when filtering the results from your potentiometers is that the aero forces are transient too, and can vary quite significantly, especially at very high or very low rear wing angles where either it or the diffuser may be near stalling, respectively. You can get quite sizeable aero fluctuations but normally they're quite high frequency (up to 30Hz ish), relative to the natural frequency of the chassis/suspension (~5Hz), so the car can't really physically respond to them in a dynamic sense and it just appears as buffeting. Sorry to add that extra layer of complication to your filtering problems.
