Your question got me wondering as I did the update 3 weeks ago on my Z690 Hero. I haven't noticed any difference as my sound seems fine anyway, but I had assumed that the firmware was stored on the 4082. Think we both have the ALC4082 chips, but I found some information on the ALC4080, which I assume will be very similar, here:
https://www.igorslab.de/en/the-old-alc4080-on-the-new-intel-boards-demystified-and-the-differences-f...There is an image on that page which I have uploaded here. It shows a box drawn within the chip schematic which says 'flash'. So I can't be certain, but it seems reasonable to assume that the firmware is on the ALC 4082 IC itself, rather than the BIOS.
Z690 Hero, BIOS 3501, MEI 2406.5.5.0, ME Firmware 16.1.30.2361, 7000X Case, RM1000x PSU, i9 12900K, ASUS TUF OC 3090TI, 2 x 16GB Corsair RAM @ 5200MHz, Windows 11 Pro 23H2, Corsair H150i Elite AIO, 4x Corsair RGB fans, 3x M.2 NVME drives, 2x SATA SSDs, 2x SATA HDs.
