A way to sort tabs within the Source pane alphabetically by a click might be a minor but useful feature. When I use R code (named 01_.., 02_.., 03_..,) in a project I usually don't open them in order of their number, but eventually end up manually sorting to keep things aligned.
Thanks for the feature request! We're tracking these kinds of improvements in this issue thread:
Can you give it a thumbs up just so we have some idea of the relative priority of the request?