I don't know if anyone has thought of this, but it is a PITA to get your Custom Lists in alphabetical order.
So, when I make a Songbook entry, I have started editing the Genre name, changing it to MINE. You could call it anything.
Then, from the main Songbook, you can choose Filter, enter Mine in the field, and all your songs come up in alphabetical order.
You can do the same with Artist field if preferred.
You could make various lists this way by making up your own Genre names, like Slow, Fast Shuffles, Half-fast. . . whatever, in the field.