Lots of text warning
While it seems like @ipalm is referring to SDH vs non-SDH being selected by default based on how your subtitle preferences are set within your account, I would like to refer to your question 3 posts up and also the preference of SDH vs non-SDH.
1st, it would actually be nice if on the account level you can say whether you prefer SDH vs non-SDH subs for when subs are auto-selected based on the audio and subtitles settings. I would prefer non-SDH subs personally, but my mom his hard of hearing and she might prefer the SDH subs because of that. So having that as a preference would actually be really nice and honestly probably help with this issue for @ipalm.
2nd, about your question about how the subtitles should be displayed in the menu, I think displaying them alphabetically based on the language name and then type (regular, SDH, forced) would probably be the best. This would keep the languages together and not mixed like in your screenshot. While at the filesystem level it might be like that, I think from a UX perspective of a media platform, the same languages being together would make more sense.
Also, related to the menu for when there are a mix of internal and external subs, it would be nice if we could have a preference (server side as it would be based on what the admin of the server decides) to either have external subs listed first and then internal or vice versa. Right now, if you have both internal and external, the external subs are listed last. Emby, on the other hand has external subs listed before internal because they feel that those would generally be the preferred subs. In my opinion, it would be nice to be able to decide that as the admin.
However, if it were possible (and honestly I think it would be, just maybe a little extra coding needs to be done), I think the best option would actually be if the server admin could have a preferred subtitle language and have those subs show first and then the rest show alphabetically by language name, regardless of whether they are external or internal. However, even without that first part, I think having the subtitle menu sorted alphabetically by language name and intermixing internal and external subs would be the best. This way, if you have for instance, internal and external English subs, they would be next to each other. I have files like this where I have the regular subs and SDH subs that are external but also have commentary tracks and there are subs for those. The current setup would have the internal subs before the external subs, so if there were multiple subs for other languages, the first English subs someone would come up would be the commentary subs. Now in my case, I am pretty good setting the track name for internal subs in the MKV properties and so it would say audio commentary but someone could also see those subs first and think there aren’t any subs for the movie.
They are probably smallish improvements, but I think they would be nice to have and are those quality of life type things. Are they really necessary, not really, but it just makes the overall experience better. Plus, I know at least one of my users has mentioned how they dislike the fact that the English subs (in my case since I only make English subs external) are all the way at the bottom of the subtitle list.
-Shark2k