billd91
Not your screen monkey (he/him) 🇺🇦🇵🇸🏳️⚧️
For the simple reason that you claim that a being alert to a threat that has taken an action is still flatfooted, which is a clear violation of both the intention of and letter of the rules. And you've been very clear about why you want to bend the rules, because you think that rogues aren't powerful enough without your interpretation and because you are clearly emotionally invested in a certain cinematic outcome.
Sorry, I don't think that's even close to the intention or letter of the rules. Flat-footed basically just means that you haven't taken your first action in combat yet. The flat-footed character could certainly be alert to the threat and still be flat-footed simply because they haven't reached their initiative yet and thus not actually had time to react. That's a far cry from not being alert to a threat.
In game terms, thanks to the glossary in the 3.5 PH, flat-footed means:
PH said:Especially vulnerable to attacks at the beginning of a
battle. Characters are flat-footed until their first turns in the
initiative cycle. A flat-footed creature loses its Dexterity bonus to
Armor Class (if any) and cannot make attacks of opportunity.
And that's pretty much it by the rules. It has nothing to do with not being alert.
Note that feinting does not actually cause the target to be "flat-footed". It just causes the target to lose their Dex bonus to AC for the next attack by the feinting character.