Technically, a lower ride height should be beneficial mid-corner, by lowering the CoG and therefore lateral transfer.
But it is very much dependant on the ARB/spring/damper combo.
Likewise, if the car is loose in a med-high speed corner, stiffening the rear ARB can provide more grip by transfering more weight to the inside wheel, as opposed to the common conception of softer=more grip (this is generally true for low speed corners).
I prefer over-damped low speed settings and stiff ARB which allow for a slightly softer spring (for grip) without compromising platform stability.
Ride height for aero is predominantly governed by the floor configuration, ie. splitter size, flat floor, diffuser, etc. although there are effects from the upper-body.