Backspace should remove full @name when the @name is added automatically in a reply

Sorry about the clunky description in the title. So my point is that when you click on reply on a post and you get the text box to write a reply, the usernames of all mentioned people get automatically added to the text box. This is good. But if you want to remove one or more of them, you have to press backspace multiple times, since it works like normal text, removing one char at a time. The username is highlighted in yellow, so the box is aware that it is one thing, and you never need to only remove singular characters from such a username. So having it just remove the whole username when you press backspace, like e-mail clients does with e-mail addresses, would be very nice, IMO :)

Thanks so much!