If you select some text in the R console, you can't type any text in it. This is very annoying, because I often end up selecting one or two characters inadvertently when I click on the console to focus it: when the mouse is moving, it's very hard to avoid selecting something.
It took me months to understand why, seemingly at random, I couldn't type anything. I can imagine this may bite people at times, which gives a very bad impression.
As I don't see the reason why typing should be disabled when text is selected, I suggest changing this behavior (unless that's a technical limitation).