There is a "Prefer subtitles in " now in the Plex settings - languages. For those who are hard of hearing, it is important to always start with full subtitles, but if a media has both forced and full subtitles, it currently sets forced as the default. So it needs another line: “Preferred subtititle type: Normal / forced /SDH” If the SDH is selected, then all media starts with SDH subtitle, if it avaiable, otherwise the full starts. . If the forced is selected, then all media starts with forced subtitle, if it avaiable.
There’s already an existing suggestion discussing an option to automatically select regular or sdh subtitles. Please comment/vote in that thread in order to help us avoid distracting or cannibalizing votes. Unless I’m missing some unique aspect of your suggestion I’ll close this thread as a duplicate.
2024 clean-up: duplicate