As mentioned elsewhere in the SDL Community, it is highly desirable to be able to use the mouse to select text on the source side of Studio Editor and drag it to a specific point in the target text, thus copying it to that point. This functionality has featured in other CAT tools going back many years. It is applicable to words and phrases in the target language, brand names, part numbers, product codes, etc. etc.
In an ideal world, this functionality would apply to copying text from any open Windows application.