I have only owned my i4 e35 for two months, but I have covered almost 10.000 km. What I also have is extensive experience tweaking the suspension on my cars. Subarus and BMWs.
I agree, the steering is a little slow, but camber isn't the first place to start. Camber will affect grip levels.
I haven't had time to do any work on my i4, but if it's anything like my previous 3 BMWs, the factory setup has too much toe-in on the front. Even compared to BMWs own specs.
Get an alignment done, and have the toe-in adjusted. Do NOT go for actual toe-out, but go for less toe-in. Stick it on the edge of the tolerance.
This will liven-up the steering response.
Toe-out will give you a nervous car, that never settles down. It will sniff out any bumps/ridges in the road surface and tug on the steering.
BMW i4 has a LOT more negative camber on the rear, compared to the front. This is a safety choice...when you boot the throttle, BMW want the instant torque tamed a little, so the car doesn't oversteer you into problems.
Try the less front toe-in, before you do anything else
(I have usually ended up with the same toe values front and rear, but I am not sure the i4 will respond well to that. )