But that's my point, wouldn't flashing a BIOS 22 times be more unwise than doing it once? Insofar as "opportunities for bricking" are concerned.
At the end of the day OP, it's your build, you're going to have to flash the BIOS yourself. All we can do from this end is suggest
"do this" or
"do that". How you consume and apply that suggestion is up to you.
I don't disagree with you at all. In fact I've said as much for other manufacturers, but not Asus (I've had many Asus mobo's - Yeah, I know, I'm a sucker for branding ).
And I also agree with being cautious. There's no harm in it, if the OP wants to do that. It will just take a while. But, why not be prudent, like you say!?
I actually began my HEDT path with an Asus Rampage Extreme X48(build is in my sig, AMS Build log) and have had a soft spot for their stuff...regardless of what people said. Sadly though prior to the pandemic, I've had colleagues who ended up with perfectly working Asus boards being bricked all because Asus pushed forward a BIOS update that was for a security/performance increment. Being an early adopter regardless of tech/BIOS versions/apps has it's downsides but being cautious doesn't.
I actually had to re-flash the BIOS of an old Asus (B85M-G)board using a CH341A programmer since the BIOS decided to corrupt itself and the BIOS FlashBack option wasn't working. So there are mishaps in all camps.