Before gettextization we have:

English locale:
'S_MONTH_SHORT'=> 'm',
'S_MINUTE_SHORT' => 'm',
Ukrainian locale:
'S_MONTH_SHORT'=> '?',
'S_MINUTE_SHORT'=> '?',

Now after gettextization the uptime format in web-interface with Ukrainian locale is wrongly presented as "2? 16? 2?" instead of "2? 16? 2?"
Is no problem in Russian because both the words (?????, ??????) is started from the same character "?" - it's just a coincidence.

I found a few locales in which this problem will be noticeable.

Therefore, the new approach requires you to rethink where there can be problems also.
May be necessary for you to check duplicate words in the English locale by specific script and found each occasion that require you attention?
It is clear that there are so many duplicate date formats - you can still ignore that in our case.

I fast found some one duplicates again:
'S_OF_SMALL'=> 'of',
'S_OF' => 'of',
maybe it's not a problem in other locales, I do not know ...

'S_LAST'=> 'Last',
'S_LAST_PAGE'=> 'Last',
'S_LAST'=> '????????',
'S_LAST_PAGE'=> '???????',
... it is definitely a problem.
...add others