Since most things don't have forced subtitles, it's likely that you won't be able to get them for a show.
For my config, I have it set to download en and en-forced subtitles.
Right now the Series UI shows 0 shows with subtitles even if all of the shows have en subtitles present. It would be nice to have a separate bar either for each subtitle, or just separate the forced from the others.
Similarly, on the wanted view, it would be great to be able to filter by type of subtitle and then only search within that type.