Some updates follow. I will probably now stop compiling this list because the BIOS history is now being shown again on support pages, so I am doing nothing more than spending too much time repeating information. Oh well, it was a good idea while it lasted...
H610 (Prime H610M -A/E/K/R and H610I-PLUS Models)
==========================================
ME Firmware = 16.1.25.1885v2_S_NonZ. BIOS 2014
ME Firmware = Version 16.1.25.2020V2. BIOS 2212
NOTE: BIOS 2014 does not allow rolling back
B660 (Strix B660-A Models)
=====================
ME Firmware = 16.1.25.1885v2_S_NonZ. BIOS 2015
ME Firmware = Version 16.1.25.2020V2. BIOS 2212
NOTE: BIOS 2015 does not allow rolling back
B660 (Strix B660-F/G/I Models)
========================
ME Firmware = 16.1.25.1885v2_S_NonZ. BIOS 2012
NOTE: BIOS 2012 does not allow rolling back
B660 (Prime B660M-K, B660-PLUS and TUF Gaming B660-PLUS Models)
================================================== ====
ME Firmware = 16.1.25.1885v2_S_NonZ BIOS 2014
NOTE: BIOS 2014 does not allow rolling back
W680 (Pro WS W680-ACE & ACE IPMI Models)
==================================
ME Firmware not listed. BIOS 0203.
No rolling back information available
Z690 (Maximus, ProArt, TUF, Strix and Prime-A Models)
===========================================
ME Firmware = v16.1.25.1885. BIOS 2103 (can go back to 2004)
ME Firmware = v16.1.25.2020. BIOS 2204 (can go back to 2103)
NOTE: BIOS 2004 does not allow rolling back to previous versions.
NOTE: BIOS 23xx (when released) might not allow rolling back either.
Z690 (Prime-P Models)
=================
MEI Drivers = 2229.3.2.0, ME Firmware = v16.1.25.1885v2_S. BIOS 2212
NOTE: Cannot roll back to anything earlier than 2014
Z790 (Maximus, TUF and Strix Models)
==============================
ME Firmware = v16.1.25.1917. BIOS 0502
ME Firmware = v16.1.25.2020. BIOS 0703
ME Firmware = v16.1.25.2020. BIOS 0812 (Apex & 790-A)
ME Firmware = v16.1.25.2020. BIOS 0813
ME Firmware = v16.1.25.2020. BIOS 0816
Z790 (Prime D4 Models)
===================
ME Firmware 16.1.25.2020v2_S_Z. BIOS 0805
ME Firmware 16.1.25.2020v2_S_Z. BIOS 0809
Z790 (Prime non-D4 Models)
======================
ME Firmware 16.1.25.2020v2_S_Z. BIOS 0806
ME Firmware 16.1.25.2020v2_S_Z. BIOS 0809
Z790 Prime Z790-A WIFI
======================
ME Firmware 16.1.25.2020v2 BIOS 0812
ME Firmware 16.1.25.2020v2 BIOS 0809
ME Firmware 16.1.25.2020v2 BIOS 0806
ME Firmware 16.1.25.1917 BIOS 0602
Z690 Hero, BIOS 3401, MEI 2345.5.3.0, 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.