I think i would leave the top button on the ct shirts unbuttoned as well to make the collar spread more. Can't tell it's unbuttoned with a tie.
And yeah, this jacket is definitely starting to get small. The better fitting one got snagged and i need to have the hole rewoven. But the local place has a month wait and my next interview is in Miami. The suit I'm wearing is way too warm for that. So i need to confirm dates before having it rewoven.