So my suggestion to also look (i.a.) at "
Close file when 'Stop' button is pressed" wasn't so bad after all.
You mention it always selects the first subtitle-file.
I donĀ“t know if it helps you, but there is also a possibility to default BS.Player to e.g. picking the 2nd (or 3rd) subtitle available:
(rightclick >) Options > Preferences > Subtitles [Subtitle properties]
To the right of (Close)-button you see the option:
Default subtitle [1]
(and also "Default subtitle language") Is that option (to change the number (resp.language)) of any use to you?