To flip this the other way- if I make a rules mistake, I want you to tell me; but if I screw something up and forget to take an optional effect that's on me. I don't expect you to remind me, and I definitely don't want a take-back. I own my mistakes. I think it's ok to do (remind someone) but I think good sportsmanship is actually for the other person to refuse the help.

Case in point, last regionals my first game was my maxed-out Whisper + miniswarm vs double falcons. At one point I rolled two hits against Chewie with my first attack; my opponent rolled one evade and declared he would spend his evade token to nullify the attack completely. I pointed out this would trigger gunner and asked him if he wanted to change his mind. He face-palmed and then said no; he'd declared it already and so kept the mistake and moved on.

2 or so games later in the same tournament I forgot to recloak with ACD after shooting. I noticed when setting the dials and my opponent in that game offered to let me place the cloak then, which I refused (and Whisper died horribly that turn).

From my point of view, regardless of whether it is good to offer help, in a tournament setting it is poor sportsmanship to accept offered help.

There is no mistake in his spending the Evade even if it triggered your Gunner. It may not be optimal considering the situation but there is the chance to wiff with the Gunner making his choice the optimal one. There is a choice to make there and it could go either way.

In your second example would things have been different had the missing cloak been noticed earlier? As in when you said the Phantom was done or some other time during that round. Noticing it during the next round it is probably better to let the optional effect slide but if reminded about the time it happened I think you should have taken that cloak and not felt the least bit guilty about it.

Well ya never know what the dice may roll, but if you can take one dmg vs none with gunner, unless the one dmg is going to kill you or is a crit, it's best to take the one dmg

Also spending the evade and take 0 dmg is actually probably worse as your now left tokenless.

The attacker has a better chance to hit against the defender

Imo they are quite respectable players.

Once you declared something it's not a good habit to change your mind.

Once I say I'm going to do something, I'm committed.

If I said I'm going to focus then realized I had a missle and should target lock, yo bad so sad. I declared my focus already

Same idea with barrel roll. You declare your barrel roll and direction and then do it.

You cant then see that oh I'm still in your arc, I'm going to focus

It's not so much the things you say you do but rather thing things that are mistakenly left unaddressed. If you SAY you're doing something then you have committed which is the first example; where I believe reminders should be given is when something goes unsaid when something should happen. It can be this last part where people get lazy and may do them without stating it which in turn seems to imply forgetting something is intending not to do something.

Were this a video game when a trigger like ACD comes up a person would need to say "yes" or "no" to it. I advocate for making these instance known. I do not advocate for "playing the other guy's squadron" which some have implied is what happens when you ask for the y/n responses to triggers.