That was my issue. I kept reverting but I replaced the original esm instead of overwriting it. I know how to create mods with the original Skyrim.esm/dlc esm(s) but when I tried creating a mod with the mod Vigilant.esm my edits wouldn't change. that's weird but most likely something I missing.
The string is saved in strings file (.strings / .dlstrings / .ilstrings) with the plugin name + language name (eg Skyrim_english.strings), and the link (string id) to the string is held in the plugin. This kind of plugin header has a "Localized" flag, so I call it a Localized plugin. This applies to vanilla / DLC plugins such as Skyrim.esm.
Yes tried it the other day and got all three manifests down and installed. Another tip is that I've installed them to a separate Skyrim SE 1.5.97 directory and left the "current" steam version as the latest AE version.
I wanted the same thing as @thefairlight, if you replace the _English part of the Strings files with _German you'll get the dual subtitles in the German language version of the game. So the files are now Dawnguard_German.ILSTRINGS. This mod allows having subtitles in two languages at the same time. By Vlad 254. This guide covers good modding practices for Skyrim (SE/AE) on PC in 2023. These basic modding principles apply to game versions both prior to and after the Anniversary update or upgrade. Even in our hobbies hard work is not a punishment. This guide also covers everything you need in terms of tools, files and preparation for snjr.