Has he changed in any way at all, besides the brief acknowledgement of what he did and the "restraint" he's showing by not verbally abusing you anymore?

Remorse isn't remorse without a change in how the person actually behaves.

My family would never, ever, even go as far as acknowledging their behaviours. (They live firmly in Denialand). I keep a no/low contact with them, because when I am around them I feel zero peace or comfort. I've found that I at least can't forgive someone who will actively continue with what they've always done. But I can move past it, and so that is what I have done.

I subject myself to family things if I am in that area. I do for the sake of appearance and because I am a good person and still try to be a good daughter. I'm never comfortable and in fact I am pretty much a totally different person when I'm with them. If you aren't comfortable with your brother, there is zero reason why you should have contact with him. You can still endure his presence at family gatherings, but you truly don't have to go out of your way to placate him because it's what he wants.