After seeing this setting in Visual Studio Code and BBEdit, I can see this being a great option to have that we can overwrite by using the setting syntax specific settings in Sublime.
Why don't I just use VS Code? I am not a developer. I looked into building my own extensions in vs code. It seems very complicated and turned me off. I little python goes a long way with ST. I have a lot of python extensions that I wrote to help me. From my perspective, Sublime Text is the sweet spot. Handles large files, fast, easy to extend for the non-developer, minimalistic. That is another area that I found unappealing with vscode. Maybe it is that I am getting older, but it seemed very cluttered, too many distractions even when you turn most of them off.
Sorry to digress. Just thrilled to use ST. Again, please consider adding the hanging indent as an option we can set per syntax.