Most of the time when I want an error control I find a terminal, right-click, create indicator/control etc and in future will probably use the block diagram error constant .
However, at other times, I want to start from scratch with a blank vi and need to navigate the palettes.
It always annoys me that if I am working on a front panel and want to place an error-in control, I then have to repeat the action to put down a corresponding error-out indicator (or ctrl-drag, right click, change to indicator). It is pretty rare that I would want one without the other!
I propose the option to put both down at once, for example, by ctrl-clicking the palettes to make a multiple selection (i.e. similar to 'normal' windows based selection behaviour).
(I was going to suggest making ctrl-clicking for multiple selections standard across the palettes, but I can't think of any other sensible occasions where it would be useful)