Not sure I'm ready to discuss patches, however. I have same issue but generally I use flags for indicator instead of letters. After recent update flags become squared and blurred. I think it's related. Changing version of libgnomekbd4 back to 2.30.0 helped for flags only. And I do think that “Keyboard layout indicator should respect font anti-aliasing settings”.
Not sure I'm ready to discuss patches, however. I have same issue but generally I use flags for indicator instead of letters. After recent update flags become squared and blurred. I think it's related. Changing version of libgnomekbd4 back to 2.30.0 helped for flags only. And I do think that “Keyboard layout indicator should respect font anti-aliasing settings”.