I went to 2 stores before buying my new AG pool, one sole "salt friendly" the other didn't, I went with salt for 3 reasons - the price of chlorine, convenience and the price of the pool package was somewhat cheaper. The only difference between the 2 is my pool has resin top rail, bottom rail and wall supports, I still have a galvanized steel wall. As was said, the water does not come in contact with the pool walls but your walls will rust eventually anyway. I was told by the pool store that didn't sell salt friendly pools that I couldn't add a SWG to it, not sure why.
I imagine that everything comes down to quality of the product. Even quality products can have flaws in it. I've seen photos of what a salt water pool did to top rails but without context of any info it is useless info. There are a lot of people here with SWG on their AG pools and I don't think people have had issues. My last pool lasted about 20 years and didn't have a SWG - the pool walls rusted, the bottom rail was gone but the top rails and wall supports looked good; I would suspect that the whole pool should have been looking bad or at least the top rails looking worse due to water sitting on it all the time.
I think you need to listen to one source of information, this site would be the source you should listen to. Unfortunately there are people who don't really understand pool water chemistry, not here. Please get a good test kit and take the water chemistry into your own hands, I've been told that having a stabilizer level over 100 was good by a pool store - no! I was told by an IG pool owner that AG pools are swamps - no! My AG pools have better water quality than some IG pools. People on FB probably don't have the knowledge they have here and nobody here is trying to make a sale on the pucks, floc or whatever else you "need".
Enjoy your pool! I wouldn't worry about using salt.
