How do you change the default indent size for R?

[TimTaylor]

Is it possible to change the default indent size for R?

In #3691 (comment) it says

You can configure the tab size for R specifically to override this config we set based on norms in the R community, but we can gather more feedback on whether we should change the default behavior.

but I can't seem to work out how to change it. I've tried the following in settings.json to no avail but I admit I'm quite ignorant to whether that should have worked or not

{
    "editor.fontSize": 16,
    "debug.console.fontSize": 16,
    "terminal.integrated.fontSize": 16,
    "markdown.preview.fontSize": 16,
    "editor.fontFamily": "Fira Code",
    "editor.fontLigatures": true,
    "workbench.reduceMotion": "on",
    "editor.tabCompletion": "on",
    "files.trimTrailingWhitespace": true,
    "editor.tabSize": 4,

    "[R]": {
        "editor.tabSize": 4
    },
}

[TimTaylor]

Need to use "[r]": {tabSize": 4} not "[R]": {tabSize": 4}. Arrrrrrrrggghhh 😅