I really like these cards. Being as I generally am the person on the other side of Karen's significant glances, I will vouch for their efficiency in the hands of a competent user (her). I'm especially a fan of the fair cop one.
That said, this unspoken communication is inherently imprecise and sometimes errors can amplify as one of us wordlessly replies to what the other silently suggested with a tilt of one eyebrow, until naught is left but an immense vague possibility spectrum.
I think being able to occasionally curtail such a blossoming range of interpretations with one of these exact, no-nonsense cards would be very helpful.
PS. Sorry about this morning.