you can have the the numbers.png file there - that's fine. And also the same it true for palette files for shorts. But you still need to assign them explicitly in the config.txt, like this:
numbers = "numbers.png"
shorts.num-pal.pa = "pal-pa.png"
shorts.num-pal.pb = "pal-pb.png"
shorts.num-pal.px = "pal-px.png"
...
(i can make this the default functionality in the next release, but you'd still have to specify palette files for shorts in the config.txt... will have to think about that one)
numbers = "numbers.png"
shorts.num-pal.pa = "pal-pa.png"
shorts.num-pal.pb = "pal-pb.png"
shorts.num-pal.px = "pal-px.png"
...
(i can make this the default functionality in the next release, but you'd still have to specify palette files for shorts in the config.txt... will have to think about that one)