I can't disagree with this, but in my experience, the time reduction it is at least noticeable.
I had recommended this approach because I saw an improvement of 5 seconds on a scheduled R script that I use for data collection, just by replacing
:: and in my use case, that little much, was meaningful, although I recognize I can't generalize solely based on this experience.
EDIT: Now that I think about it, maybe the difference that I saw, was do to the fact that usually when we use
library() calls we put them at the beginning of the script and when we use
:: the namespace is loaded in the moment the line of code gets executed. I naively was judging the time reduction based on time stamps recorded in my database, so I was fooling myself.
Sorry for the misleading comment