Just wanted to double check before I got something wrong.

You have a ship with Overclocked R4, Deadeye and Proton Torpedos.

During combat you have a focus token and want to spend it thanks to Deadeye to shoot of your Proton Torps.

When exactly does Overclocked R4 kick in?

I assume you have to decide if you want to use him or not before rolling any attack dice.

However I found no proof for either or, so I wanted to see if I'm right on this one.

Thanks a lot for answering, cheers!

That seems correct - you can declare R4 when a focus token is spent, which means you'd need to make that decision before any follow-up actions occur.

I agree with Mozic. Secondary weapon costs are paid in step 1 of the attack sequence (Declare Target). Step 2 is Roll Attack Dice, so you'd need to trigger any abilities related to spending the focus token for Deadeye before you move on to rolling the attack.

You spend the focus token to fire the torpedo in the "Declare Target" step, so yes, if you use the Overclocked agromech to gain another focus token, it's available in the (later) "Modify Attack Dice" step.

Thanks for your answers

What about cool hand on defense? Can you then spend the focus, get a stress and new focus, use cool hand to get an evade, then spend evade all while modifying dice?

What about cool hand on defense? Can you then spend the focus, get a stress and new focus, use cool hand to get an evade, then spend evade all while modifying dice?

Yes. Both OR4 and Cool Hand trigger within the modify defense dice step, so you can spend the evade token right away.