REO i believe Batman's B113 is interruptable as well. Can't confirm atm
if i remember correctly if you are duck blocking B1(1) will wiff and you can punish before the 3 comes out. Also probably hitbox dependent, i doubt it wiffs on lex, grundy, bane ect
Now that i think about it it may be range dependent. like if batman does the string outside point blank range the B1 hits but the B1(1) will wiff on ducking hitboxes. Anyway sorry for the vague information, i just know i've have been interrupted during that string before but can't remember the conditions for why it was possible