Hmmm... Maybe?
I also really like ORAS a lot, Alpha Sapphire is even the first game I've ever finished the Nat Dex in. I did also get Omega Ruby at some point as well, but that was mainly for a different playthrough due to not wanting to delete my Alpha Sapphire save, and it seems you've deleted your Omega Ruby save many times. Also, there isn't much difference between the 2 evil team points of view except wanting to expand the ocean instead of the land. Although I'm pretty sure there is something in the Aqua hideout explaining Shelly's backstory, which I don't think is in Omega Ruby for any Magma character. I'd buy it if you just want to do stuff in Alpha Sapphire that Omega Ruby doesn't have, which is basically just version exclusive pokemon. The 2 evil teams aren't really that different in both games. Although I do forget if there are any other version exclusive stuff, I think maybe mega stones during the story?
tl;dr don't buy it unless you wanna see tiny details like version exclusive pokemon, use of different mega stones during playthrough, Shelly's backstory, etc...