Originally Posted by
AmarokGTI
If you are not getting the required deceleration changing the setting might not work if the reason is a fault with the system. Once you work that out you have even less time for the manual option.
I'd only use it the other way around:
Say you've prepared performance rollout data for a WET runway but during landing its damp at best if anything.
Having checked DRY and WET performance prior to landing, you know that a lower AB setting would make the desired exit in DRY conditions.
Lowering the AB eating to the desired lower one is good airmanship in this case, alternatively, manual braking to disconnect the higher auto brake selected the other option.