The softer spring rates we use mean less sensitivity to corner weight differences. There are three elements:
Weight ratio Front to Rear
Weight difference Side to Side (ballast)
Cross weights - Right Front vs Left Rear & Left Front vs Right Rear
For braking stability it's very desirable to have equal weights in the front L/R
Weight dffierences side to side can be adjusted via moving the battery, spare etc.
Cross weights have a greater handling effect with cars with higher spring rates but does have some effect with road cars negotiating left vs right hand corners. A link to a good article that explains measurement, the effects and means to correct.
https://grassrootsmotorsports.com/articles/understanding-corner-weights/