problem with polish diacritic signs

I was trying to find a way to make Tonic display polish diacritic signs properly. Finally i managed to do so by adding a line “&subset=latin,latin-ext” to the code where googleapis links are inserted.
I’m asking the author to put that line there, so i didn’t have to change add it manually every time the theme gets updated.
Me (and i guess all my polish folks) would appreciate that.
Thanks in advance.