so it comes down to 2 possibilities I feel

1. Because you are able to spend it during the attack, you can't do an action which would stop you being able to spend it, for example Accuracy Corrector, before you spend the focus.

2. You get to choose the order of operation, so can choose to use Accuracy Corrector first, at which point you are no longer able to spend the focus token.

Yep, and well-summarized.

FWIW, the intent is #1, but (while it's pretty easy to see the intent) the wording does not make that intent iron-clad, so it will need a FAQ. And, intent notwithstanding, I don't know which way a FAQ will come down. If I had to bet on it, I'd bet on #2, because that's the easiest way.

so it comes down to 2 possibilities I feel

1. Because you are able to spend it during the attack, you can't do an action which would stop you being able to spend it, for example Accuracy Corrector, before you spend the focus.

2. You get to choose the order of operation, so can choose to use Accuracy Corrector first, at which point you are no longer able to spend the focus token.

Yep, and well-summarized.

FWIW, the intent is #1, but (while it's pretty easy to see the intent) the wording does not make that intent iron-clad, so it will need a FAQ. And, intent notwithstanding, I don't know which way a FAQ will come down. If I had to bet on it, I'd bet on #2, because that's the easiest way.

tbh I don't think we can know the intent, it's a fringe case and I'm not even sure they thought of it. I could see them falling either way.

The way I have been playing with hotshot is that I call it out at the last chance IE: before I roll my green dice when I'm defending, or before compare results when I'm attacking. Since that's how I'm playing it someone could block me with Accuracy Corrector if they attack before my hotshot.

My current lists I'm trying with hotshot have it on ps9 so I'm forcing the focus use on their defence, making it unavailable when they return fire. Forcing a decimator/ghost to use their focus on defence saves me a lot of damage when it's their turn to fire. Likewise for defenders that want to use Palp + evade to dodge me: too bad they have to spend focus, now it's not there to use on their attack.