dlig feature help

I'm doing this discretionary ligature feature where the substitusion part looks like this so that it works with lowercase, sentence case or uppercase. I wanted to make an OpenType class, but that won't work for ligatures, right? I'm just typing all this out by hand, just wondering if there's a way to condense the code at all.

Almost forgot to add this is an all caps font so as to why all resolve as an uppercase ligature.

    sub a b by AB;
    sub A b by AB;
    sub A B by AB;
    sub aacute b by AacuteB;
    sub Aacute b by AacuteB;
    sub Aacute B by AacuteB;
    sub acircumflex b by AcircumflexB;
    sub Acircumflex b by AcircumflexB;
    sub Acircumflex B by AcircumflexB;
    sub adieresis b by AdieresisB;
    sub Adieresis b by AdieresisB;
    sub Adieresis B by AdieresisB;
    sub amacron b by AmacronB;
    sub Amacron b by AmacronB;
    sub Amacron B by AmacronB;
    sub abreve b by AbreveB;
    sub Abreve b by AbreveB;
    sub Abreve B by AbreveB;
    sub aogonek b by AogonekB;
    sub Aogonek b by AogonekB;
    sub Aogonek B by AogonekB;