This occurred to me as I was trying to edit .Renviron in an RStudio project that was equipped with project-specific .Renviron. Naturally, I was editing user .Renviron as this is the default for edit_r_environ() only to see that it had no effect. You could detect if there is project-specific .Renviron and issue a bullet point in edit_r_environ() message to remind the user that different .Renviron may be taken into account.