I use the fluid motions Quattro double boot. I have never heard of someone hurting their ankles or feet , with these. In slalom your ankles are the weakest link as far as injury goes. Excited to see what the future of ski boot design goes to.
Have been on fluid motions for 10 years always released when they should. Never any issues! Tore my tendons in my front foot twice with rubber boots. Will never use a rubber boots again!!