Are you having the "blank screen during boot" issue? If not, don't worry about the update. I have the TUF 4090 OC on a Hero Z690 and don't experience the issue.
As for the ASUS BIOS update, I'd do that as it fixes a few issues such as underperforming when the card is only slightly loaded. There was a v1 version of the firmware tool (which was subsequently removed) and now V2. If you had already applied v1, there is no need to apply v2 (it just fixed a few incompatibility problems some users were experiencing when trying to use v1).
I skipped the Nvidia bios one since I didn't have the issue they supposedly fixed. I flashed the v2 BIOS a few days ago when I got my TUF 4090 and came to the forum today to find that there's a new one. I'll flash it tonight.
Hopper64 wrote: I flashed V2.1 on my Strix OC card with no issue.
I wonder if that BIOS will resolve Armory Crate not seeing my card at all. I’ve jumped through so many hoops and reinstalled windows multiple times and I still can’t control the RGB for my Strix 4090.*