The Mach 5.5 did it again!
If you use the word garbage, be careful, it might bite back.
Regarding flex/derate/assumed take off:
You cite best industry practice. Well, it's not completely true. With the EK software, you can only go for full thrust or max reduction. Any in-between, which is used a lot elsewhere for a little more safety margin but not full thrust, is not recommedable here, because the gross error trapping procedure a la EK will no longer be possible. It's not in the SOP, so either full or full reduction, which I believe is not best practice.
Regarding surge and fireballs:
A surge does NOT necessarily have a fireball, and you pretend it is to be expected. It may or it may not. If there is a fireball however, I would NEVER rule out a possible real fire, as you so brilliantly do by pretending that this is absolutely no fire.
By the way: How do you know that fatigue has already been ruled out? The prelim is not out yet, isn't it?
The more you post, the more you seem like a seat cushion warmer in the obscene palace, but not someone confronted with the real garbage happening on line with EK.