Hi, Chris! Let me offer my condolences. I've had similar experiences with my dad. The situation between us even today is bad.
He's ancient and I'm not young, and we've never resolved our differences. Looking back on things now, I wish I'd come out as trans to him long, long ago, and I wish I'd taken on a number of other issues as well. He wouldn't have liked what I had to say one bit, but we would have had years to try to come to terms with each other.
As it is, I'm not even out to him. He still doesn't know I'm trans. We live thousands of miles apart, so it's easy enough for me to keep things secret, but I don't like the situation one bit. It's just that old and set in his ways as he is, not to mention his fragile health, my brother and sister and I all agreed that we needed to keep quiet about it because he simply wouldn't be able to handle it.
Not a great situation. Also, in discussions/arguments we've had in recent years, he's made it quite plain that in certain ways he has no respect for me whatsoever. He's got issues himself that he never even wanted to recognize, let alone deal with.
So I don't know what to say to you, apart from the fact that you've certainly got my sympathy. I can say that I wish I'd dealt with things one way or the other when I was young. A whole lifetime has gone by, and the issues that always separated us are still there, unresolved.
I don't think you need to do anything straightaway. Maybe you want to take your time, months or even longer, to mull things over. But if you decide you want to tell your SD exactly what you think, exactly what your problems are with him, you never know, he might eventually decide he'd like to patch things up with you and try to have some kind of relationship with you, even if it's not the ideal one you'd like to have.
My feeling is (going by my own experience) it's best to get things out in the open as soon as you can and not let them fester for a lifetime. If the result is that you simply can't get along with him, at least you know that much and you don't spend your whole life worrying about it.
But these are just my thoughts. I can't tell you what to do in your life. Only you know your own circumstances, so you'll have to make your own decision. I just wish that I'd done things differently when I was young.
I wish you all the best, in this respect and in all others.