Why Is there No rear Spring Rate Options?

Today I am looking a bit more on the advanced options and I try to raise the suspension as high as it can go or as low. Fortunately I cannot do it for the rear springs as the option is not there, should it be??

 

Putting off-road shocks on the rear will give you those abilities. Even though they usually sit high, you can lower them quite a bit.

 

Thanks for that, Ill check it out
--- Post updated ---
Im achiving some cool experiments, thanks man