Well the first and foremost reason for the liner is to be able to wear a smaller size boot (it’s thinner than the stock liner), it’s pretty popular in the inline scene these days. Though it does Provide some extra support high up which helps with responsiveness, theyre particularly popular with bigger wheeled skates cause the higher ride height can use all the support they can get. I skate quads and I live in California too btw haha! A CaliRollerthemmmm ya could say ;)! Working on a design for aluminum roller skate plates that can mount to any aggressive inline boots and also a sibling mode for the 165mm heeled skates as well with adjustable truck positions so quad people can see the advantages of modern boots plastic and otherwise.