We have had salt in our AG pool for many years. I took it apart to install a new liner, cove, etc last year. No signs of corrosion
I am thinking of a SWCG for the pool I just bought. Its a Sharkline Morada/Quest. I believe the only parts not resin are the uprights and they are coated with an anti corrosion compound. I have heard that you must have an all resin pool to use a SWCG. My internet dealer says my pool is not warranted for a SWCG.