As someone who programs in modern APL (no joke check out dyalog) I think this is terrible. Besides the APL characters are just the greek characters, and all sorts of things use those.
The original keyboard design was meant to be used to type the characters present in the APL code page [0]. My intention was that one would still be able to type the same (or perhaps mostly the same) characters as the original keyboard but using Unicode instead the APL encoding (which is based on EBCDIC, yuck).
My design may or may not contain the same keys, because I am not sure how many would want the original APL character set.
APL keyboards are available, so the market exists [1], but that doesn't mean much. I plan to have the micro-controller user-configurable and replaceable, so one could change what symbols were type-able with the same keyboard. As I expect to use UTF-8, this keyboard could be used to type any character in the UTF-8 code pages.
