Have there been any rulings or rules changes that affect any "would be kod" effects?
Like if Deathlok WaTX 11B who has (COMPUTER: NO KILLING PROTOCOL: The first time each game an opposing character would be KO'd by Deathlok's attack, instead turn them to their last non-KO click.) were to hit a character from the CA&A set with any of the traits like:

Living Legend: The first time each game XX would be KO'd, instead turn him to his last non-KO click, then roll a d6 and heal him equal to half the result. Protected: Pulse Wave.

Last I remember, the active player may apply simultaneous effects in any order. Still correct?

From the CRS. Since only one effect resolves, we could debate on whether the second one would be eligible to trigger the next time around based on the 'once per game' sidebar, but I don't think it's really the same and I would say only one of those effects, of the active players choosing, would resolve and the other one will be ineligible for the 'second' would be KO'd.

What’s there to debate?
The fact that cancelled “Once per game” triggers can be used again later is covered by the rules you quoted:

Neither of those effects say 'once per game'. They are both 'first time would be KO'd'. Some will try to reinterpret this as being equivalent to 'once per game' as you have demonstrated, but really they're looking for a specific trigger, not just any time they would be KO'd, but the first time only. Just because the other effect didn't have a chance to resolve, doesn't mean it's the first time again when it's really the second time.

Ah, I see. Thanks

Thanks for the help.

So if anyone plays Prime Deathlok, the attacking player can now chose the effect that the damaged clix goes to its last click, and will not roll a D6, correct?

That's Correct.