Bios Update and Custom Settings

[Romarco]

I understand there is no way of updating a motherboard's Bios without loosing all the custom Bios setting.
This awareness (combined with laziness) always held me back from updating.
But last week, with the latest release, I realized that maybe I'm too far behind (almost a year) and I should really update, even if my PC runs fine for my needs.

So, already knowing that after the update I'll have to manually restore my custom settings, I wonder:
is there a way to know exactly what are, in the Bios, ALL the differences between the current settings and the default ones (which be presumably restored by the update process)?

[kvarq]

I was able to load the *.cmo settings from an old bios to a new one on Z490 and Z590 (both of them ROG Apex), suprisingly
if there are new or moved options from a version to another these have to be applied manually; no errorrs are reported, so if something is changed from a version to another it will be unnoticed, so an overview before the actual restart would be recommended

this comes pretty handy when testing different versions, switching from a version to another

but when I am planning to use a bios version for a long time / daily, I prefer to apply all the settings from scratch, takes maybe 10 mins or so adjusting all the stuff, including fan profiles etc., to be sure I'm going through everything