Lots of us on this forum have SWGs in above ground pools. From a practical standpoint, the corrosion risk is minimal and not really any different with our without an SWG since chlorine, regardless of original form, leaves salt behind. The level of salt that an SWG needs to operate is 1/10th of the ocean.
It could possibly effect the warranty, but those warranties tend to be pretty worthless as I recall. Like each year they cover less and less, and only parts (not labor) and you have to pay for shipping both the defective part and replacement part, and they will likely blame it on bad chemistry in any case.