Well, he did f*ck with Roman's sh*t from at least Batman issues #635 to #649.
I mean I think if he confronted Black Mask now in comics that would be a helluva sh*tstorm. (Apparently Jason also knows "who" Black Mask is, anyways, but then again, that's from BftC. And well..... Ugh.)
I'd honestly like to see a day where Jason kills the Joker, Batman watches or something. I think if anyone's going to kill the Joker, it would be Jason. (I don't want to say he's the most "deserving" of it b/c there's a lot of people who would want the same chance and feel just as "deserving" I'm sure, given that by last estimate, he's killed something like 2,000 people.)