The major questions are 1). how close is your storage to saltwater? 2). Is it inside or outside?
The first year we had our GT325, I put the jacks down to take the weight off the tires. Despite regular wiep-downs with hydraulic oil and cloths, the piston rods of the jacks got light corrosion in the 4 months they wre exposed. It cleaned off relatively easily, but, with an airplane hydarulics background, I wasn't comfortable.
I contacted the manufacturers for guidance, and they replied that if you're storing it close to saltwater, don't leave them down for extended periods. They defined "close to" as within 60 miles. We're within 60 yards, across the street from a saltwater marina!
I guess the tires will have to handle it. Once a month, I jack it up high enough to lift the wheels off the ground, one side at a time and rotate the wheels by hand a quarter turn, then put it down again.
Frank and Eileen
No longer RVers or FR owners