Foote:
How I have believed it works, largely because of the two threads you linked:
Static triggers don't have a timing, as in they don't have a yes or no timing. Triggered responses (like win conditions on villain cards) have a moment where they trigger or not. If there aren't enough citizens in play second side Dawn doesn't flip, even if the next step is to put the last needed Citizen in play she won't flip, even though it is still the start of the villain turn, the time for that trigger has passed, it already failed.
Imbued fire does not work that way. Anytime the damage is fire it gets boosted, which is why it doesn't have timing, it does not have a yes or no check that can't be redone, like triggered effects have.
If both imbued fire's effects were worded to be trigger effects then only damage that started as fire would get the +1, damage changed to fire by Imbued fire would not get the bonus, because the check would have failed, and would be done.
Multiple static effects do not have timing problems. They can't.
Static effects can have timing problems with triggered effects, which is why Fort/SHD is resolved by the order they came into play.
The way this would work is static effects have timing of application, they do not trigger, but they do have to be applied.
If Imbued fire is out and Wraith has micro and would deal projectile damage (at a conditional +2) it is changed to fire, where it loses the +2 for projectile and gains a conditional +1 for being fire damage. If she had TtE on her and Visionary changed it back to Projectile damage it would lose the conditional +1 for fire and regain the conditional +2 for being projectile.
All of those events occured, and had timing of application. That is why fortitude and SHD can occur simultaneously, because as soon as the damage is being dealt to Legacy both would occur, Fortitude would be applied, and SHD would trigger, 2 effects simultaneously. This is the only way I can reconcile the rulings, and I think it is how they see the game.
Let me be clear this is why I do not like the official methodology. It forces keeping track of too many card timings, and in most of my games I let heroes decide the order of those interactions, because that much bookkeeping lowers the fun value for me, and more so for the people I game with.
I like your explanation better, and it follows the way I do my games, but I don't think that is the way they see it.