It seems that setting:

heading = { 
fontName = Menlo
};

Should obviate the need to specify the name again in a subsequent:

heading1 = {}

declaration. But it does not appear to work that way. For example, the following doesn't work to set the heading1 font size:

heading =  {
    backgroundColor = 0c000000;
    fontName = Menlo; 
};
heading1 = {
    fontSize = 20;
};

but this does:

heading =  {
    backgroundColor = 0c000000;
};
heading1 = {
    fontName = Menlo;
    fontSize = 20;
};