ok, so from what i can gather, nothing really jails into batarang, except for doing 12~mb batarang on superman, for some reason on everyone else they can backdash the explosion. That being said, if the opponent is ducking, up batarang will whiff, however, doing b2~up mb batarang will prevent this as the 2nd hit is an overhead, so the opponent would have to make a super hard read that you were gonna do the batarang and duck, which if u did the rest of the string would hit them, and if u had bats available thats a full combo with mb grapple. theres also the opiton of cancelling your b2 into bats and then go into more pressure.
another option may be doing 11 into up batarang since 113 is an overhead, the overhead is also majorly plus (+ 6 i believe).
so mb up batarang is usuable due to the mind games batman has from the overhead into his string. make use of this and strait ex batarang in your pressure. f23 will only reach after up batarang. after blocking a mb straight batarang, doing a step forward into f3 can easily blow up back dashes.