I signed up here just to say this but I see it's already a topic.
Two minutes after unboxing my Keystep I pressed one of those buttons and I was, like, NOOOOOOOOOO! How could they? Who on earth thought it was a good idea to make those buttons flash like that?
Apart from being very, very annoying it simply doesn't work. Can anybody really tell at a glance the difference between one or two octaves up/down by the flash speed? Nope.
One octave up/down should be lit up permanently. Two octaves? Flash then, but not before, and do some sort of flash that's obvious where the octave setting is at (maybe fast 50Hz flashing for two octaves, slower flashing for three).
Can you do PWM on these LEDs for brightness? Make them increase brightness as you go up/down the octaves, eg. 25% brightness for one octave, 50% brightness for two, 100% brightness for three.
PS: Need any help? I'm a freelance programmer of these sort of devices, expert at controlling LEDs.