Look at the amount of cash going back across the counter. If he takes my $1400 check and I buy a $900 sofa, no problem. If he takes my $1400 check and I make my $85 monthly payment or buy a pack of gum, he is an MSB. Any statement from him that he doesn't cash checks would be something of a lie and put him in a position to say that you said it was okay.
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.