Subtitles time offset also for embedded subs please

hey,
so many times also the file embedded subtitles (dont mean hardcoded) are severely off sync, but the ‘time offset’ option isnt available for those. and many times there arent any subtitles available for those on opensubtitles.org.
so the ‘time offset’ option also for the embedded subtitles would be much appreciated. (basically all other media players can do it, so it is doable)
thx