Created little plugin for bsplayer 2.11. Works only for VobSub.
Just extract to bsplayer plugin directory and restart player.
Then you can:
- Backspace : toggle subtitles show/hide
'\' : hide subtitles
'0' : show subtitles
'=' : next subtitle track (work on multilanguage soft subtitles, such as .idx+.sub)
'-' (not on numeric keyboard): previous subtitle track (same)
Tested with DirectVobSub 2.37 (aka. VSFilter, aka. DVobSub).
Probably don't work correctly with multiple vobsub instances.