Do I really need Torklift Stable Loads

Blocking the overload spring will bring it into contact earlier and keep it in contact for more of the suspension travel. That increases the spring rate. Anything that increases the spring rate will increase roll stiffness. The overload is pretty wimpy though, adding around 400 lb/in of spring rate. A big anti-sway bar will do a lot more.

I wish I had invented the Stable Load. $5 of steel plate sold for $300. A license to print money.