just curious why the extra tab key for the hiragana kit? also, i quite like the unique windows key, it gives character to the set. I hope it doesn't add cost to it though.
With the extra tab, you can actually cover 2 boards with a base + hiragana kit.
It can't be any 2 boards - there are limitations, but you can do it.
One would have to have split BS, the other would need normal BS.
One would need to have 7U bottom row, the other 6.25U bottom row.
One would need short right shift, the other full size.
I think that about covers it.