A cars ride and performance are factors involved in designing a suspension. So are wear and intended service life. As you alter any aspect of a suspension you alter the whole equation. Using heavier tire/wheel combinations changes the requirements for springs and shocks and calls for more strength in all the joints. When prepared for racing, as those wheels would be functionally used, the control arms are stiffened larger brakes and bearings, stiffer (maybe different material: rubber vrs hard plastic) suspension pivots and subframe mounts (rear).
The steering isn't designed for the load so shimmy's are prevalent. Everything you change in the design of suspension is a tradeoff; handling vrs comfort. But, by only changing one aspect you wind up with poor results in both areas.
And besides, I'm a purist.
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician