We have just deployed a fix for the official opensubtitles addon and we are expecting the subtitles to show much sooner in the apps, we will also work on improving the subtitle experience for all users in the coming weeks
This last update was huge differences for Android TV users. Fire OS not so much. Android TV users press down on select button, icon on far left at the very bottom allows you to select different versions of Open Subtitles. You can use the gear icon to adjust the offset between the spoken words and the subtitle text. With practice, you can get a match but it often needs another adjustment. Honestly, 1.5.7 is so horrible for those of us who are hearing challenged that motivated me to start the thread on advantages of Kodi, which @elginherd addressed so well.