If the testing is unconscious on the part of the woman, then how much of this testing is just men feeling insecure and wanting validation from women? And what could repel a woman faster than an insecure man who constantly needs to be told things are ok?

I think a confident man who is secure in himself probably does not have this problem often. Similarly, a confident woman who is secure in herself is probably not out here testing anyone, insecurity is obvious and easily avoidable.

Maybe the "plenty" semantics is just a numbers game. Of all the woman I know, the vast majority would not trifle with those types of games. But a small proportion absolutely love playing mind games on insecure men because it gives them a thrill, maybe that smaller proportion reads as a larger part of the population to men via a variation of prospect theory?