When I use my iphone, Web app or other, when I set the audio or subtitles, everything works.
But on my Apple TV plexconnect don’t respect my choice of Subtitles or audio.
The Apple TV settings override those of plexconnect.
It really isn’t that easy… I think PlexConnect tries to honor the setting, as long as it has the ability to do so - that is, if you have media/subtitle formats that don’t use the aTV native subtitle engine.
If you are using mp4/embedded subtitles however, everything on the player side is handled by iOS. And we haven’t found a way to override that behavior.
There might be other filetypes or situation where it doesn’t work as expected, but to figure that out we need more information: filetypes, codecs, subtitle format…