Hi, A bug was filed recently a about the Cyrillic letter i being too low. https://savannah.gnu.org/bugs/index.php?22289 It was indeed, strangely a bit lower than other flat-topped Cyrillic letters.
I assumed this was just a glitch, maybe a slip of the mouse; it is fixed in the latest release. However, I revisited Cyrillic recently, and in Serif anyway, found that this inconsistency happens in many other letters, as though the range were composed from more than one font. Indeed this was the case. (A quick check of Sans and Mono didn't turn up the same sort of problem.) Also, most of the letters in the Russian alphabet are substantially taller and heavier than their Latin counterparts, by a good 6%. Just enough to be visible at normal text sizes. That's poor. Before I launch into a repair by hand, I thought it might be best to ask the list for advice. Is there a preferable way to fix this problem?