Sorry I did not check yet if your "lib" will trigger this problem too but I guess it does.
Original ticket at Microsoft is here: https://connect.microsoft.com/IE/feedback/details/831964/font-feature-settings-with-open-sans-webfont-in-win7-ie-10-11-no-text-problem
It only occured for "Open Sans" for me but there may be other font that trigger this which basically destroys the page completely, somehow in IE10/Win7 only.
So this may not be a problem your code should prevent but maybe a note on the front page to look out for this possible problem would make sense.
Sorry I did not check yet if your "lib" will trigger this problem too but I guess it does.
Original ticket at Microsoft is here: https://connect.microsoft.com/IE/feedback/details/831964/font-feature-settings-with-open-sans-webfont-in-win7-ie-10-11-no-text-problem
It only occured for "Open Sans" for me but there may be other font that trigger this which basically destroys the page completely, somehow in IE10/Win7 only.
So this may not be a problem your code should prevent but maybe a note on the front page to look out for this possible problem would make sense.