There are some things that one should never say.

One of these is the phrase “Be that as it may,” such as, “Your
argument is a cogent one, but be that as it may, I don’t agree.”  By
my understanding, “Be that as it may” is the polite way to say,
“F*** you and your stupid argument.  Here is what I think.”

“Agree to disagree.”  This is a favorite of the “Can’t we all get along” crowd, as in, “My views are different than your views and as we will not come to a mutual understanding, let us agree to disagree.”  I much prefer to say, “Let us agree that one of us is wrong and just differ on which one of us it is.”