Work on the custom sort is going on, it's bolted on Arcadeflow right now and seems to work pretty well, but I had to tweak so many things under the hood that I need some more time to debug it...
One question for all the users: how do you think "next letter/prev letter" should work? I mean, by default in Attract Mode if you are at letter G, and you go to next letter, it brings you to the first item of the "H" letter, and if you go to prev_letter it brings you to the LAST item in the F. I tweaked Arcadeflow so that it always bring you to the first item of each letter, but maybe this is not intuitive. What do you think?
And what if the list is reversed in order? Should it work the same? Or change?