I take it that you're nitpicking my grammar because you disagree with my views.

I was (and am now) nitpicking your semantics, in order to establish your meaning.

As for what topic I am talking about, it is this: In the most practical sense, what you did yesterday has already happened. What will you do five minutes from now? Let's call it Z.. Yes, as a human agent the body and brain running the program you call yourself is the one who appears to make those decisions five minutes from now, but six minutes from now Z has already happened.

The fixity of the past does not imply the fixity of the future.

In this practical universe there is only one Z,

Before or after it happened?

and you can imagine all you like that Z could have been otherwise, but six minutes from now, IT WASN'T OTHERWISE.

Four minutes from now it might have been. The fixity of the past does not imply the fixity of the future.

There may be queeftillions of other universes where a probability bubble in one of your neurons flipped a different way, but those make absolutely no practical difference in your own life.

Free Will isn't less important than a practical difference, it is much more important. It affects what makiing a difference is. If FW is true, I can steer the world to a different future. If it is false, i cannot make that kind of difference: in a sense, I cannot make any kind.

You're not enslaved to physics,

Whatever that means.

you still made the decisions you made, you're still accountable according to all historical models of accountability

As you have guessed, lack of accountability (in certain senses) is a key issue in Libertarianism.

(except for some obscure example you're about to look up on Wikipedia just to prove me wrong), and you still have no way of knowing the exact outcomes of your decisions, so you've got to do the best you can on limited resources, just like the rest of us.

That is irrelevant to the existence of FW. Nothing about FW implies omniscience, or the ability to second-guess oneself.

"Free Will" is just a place-holder until we can replace that concept with "actual understanding", and I'm okay with that.

How do you know that hasn't happened already?

I understand that the concept of free-will gives you comfort and meaning in your life

You're trying to ad-hom me as a fuzzy-minded irratiolanist. Please don't.