water softener

So I'm looking to setup my own water mixing station in my garage, rather than use a garden hose for water I was hoping to maybe connect up to my water line I believe goes into my water softener. I'm no plumber and didn't install this but from my understanding is the softener has one main water...

Next month Im moving to house that has well water and a septic system. The well water passes through a water softening system. I'm thinking that placing my RODI after the water is softened will help preserve membrane life and DI Resin. Does anyone know if there are any issues with this...