Generally, preamp mode on a standalone DAC "is an afterthought".
sorry to confuse you
No confusion, "an after thought" infers something has been tacked on, this is not the case with dacs digital domain volume controls.
As the digital digital volume option in dacs is either there or it isn’t.
If it’s there it can be activated or not and left at full output. Sorry but nothing gets "tacked on"
Cheers George