Speech, Settings - there is no Mono button, only Stereo and it cannot be switched off. Thus one cannot record in Mono, unless I am missing something here.
Here is the same screen from Audio & Music Lab:
Is this a bug or is there some way to record in mono in SFACL?
Not sure whether there's supposed to be any rhyme or reason to this change. I can't think of any. I passed it on to development as a formal problem report.