Focus stealing issue

I hate it when an application steals focus and immediately accepts as
input whatever I was typing! Let's say I am writing a letter and, all of
a sudden, an antivirus window pops up claiming it found a threat: Delete
Yes / No? Let's say I was going to write the word "youghurt" in my
letter, so I am actually pressing the Y key, and the antivirus gets it
to mean "Yes, do delete!". But I just meant writing "youghurt"!

So, my Windows 10 question is: is there a way (registry hack? third
party utility?) I can set a delay, like one second, and in that second
immediately after an application window pops up my keyboard will be
"muted", so to speak, and whatever I was typing will NOT be used as
input for the newly created window.

Even better, I'd like to be able to set a list of "dangerous"
applications for which I want the delay, because I wouldn't want it for
any applications, I guess.