Well, it gets more and more interesting with regard to Sleep Mode.  After a little experimenting, where I used a specific Notepad window (one of the three I have open) where I put NVDA to sleep with NVDA + Shift + S (Desktop keyboard layout):

The sleep is not application specific, as in any Notepad window that's open, but Window specific.  Only the one Notepad window where I put NVDA to sleep is where it remains asleep when ALT + TABbing between applications.  None of the other Notepad windows are likewise "asleep"

The duration of the sleep upon focus is for the life of that Window.  If you close the window, and open that very same text file immediately afterward, NVDA is again active in the just invoked Notepad instance.

Not that any of the above is particularly surprising, but it does indicate exactly how NVDA is handling being put to sleep:  On a window by window basis.  So the "transitory configuration profile" does not act, like regular ones do, at the level of the running application (as all instances of a given application where settings are set using a profile will inherit those settings) but at the level of the window in which NVDA sleep was invoked.
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Brian - Windows 10, 64-Bit, Version 21H2, Build 19044  

The instinctive need to be the member of a closely-knit group fighting for common ideals may grow so strong that it becomes inessential what these ideals are.

       ~ Konrad Lorenz (1903-1989)