I was initially resilient to comment but especially after noticing GB cancelation I feel the need to address the elephant in the room: so called "Polish" sublegends.
I am actual native Polish speaker writing in Polish for over 4 decades on US keyboards - instead of actual Polish typewriter layout (derived QWERTZ that would be actually closer to Prussian / German name) just to let you know, but the reasons for Polish Programmers layout are beyond this subject although simple (US imports).
I was not much exited about Polish sublegends, simply because
we get used to imagine where they are on US keyboard when we learn how to use komputer (computer), the Polish Programmers layout was designed to be intuitive (i.e. Ą = A), easy to remember and AFAIK no single keyboard with those sublegends exist on the market.
To be honest single € sublegend (on U) would be more useful as not every Pole knows that Euro sign is there.
On the other hand I can clearly see that (only) few big sticking out capital sublegends with accents might surely put off users from other nations. Personally I don't like the look myself while being Polish. It's not really like Chinese / Japanese sublegends spreaded across the whole kit with distinctly different characters to latin alphas, so you can see them as decoration / art (c'mon nobody actually use them). Adding (almost) the same latin sublegends makes no sense to me.
Don't get me wrong - I am always happy to see any Polish accents in life (especially because I am living abroad) but this is overdoing in my opinion for no practical or aesthetical value.
Thank you very much for the good intentions but plain English base would surely be more successful in GB.
PS: I would love inverted alphas but you can ignore this, it's just my distaste for GMK dark background implementation resulting with
reflections.