My wife's RF is 235/40 on 17x8, pic below. Doing same 235/40 on 17x9 will square up the tire a lot more, far more firm performance. Using an all season might even look a little stretched on 17x9, more so with 225 choice. So, if really doing all season on 17x9, I would pick the 235/40.
Note all over the site we usually suggest 17x9 is a race fitment, for those racing the weekends at SCCA events, the track, etc. We don't recommend 17x9 for street, so that's not a size we ever suggest an all season choice on, assume it may look stretched a bit even with 235/40. All season tires tend to run a little under the listed size, ultra high performance tires tend to spill quite a bit wider than the listed size. I have a 225/40 Hoosier race tire here that looks near half an inch wider than 235/40 street tires. So, the point to understand is the more aggressive tire in 235/40 will better fill out that 17x9.