For sure it is possible. Probably we'll add new option in preferences in next version.
By default we use keyboard to activate inline editor because usually you have to use keyboard anyway (to enter new value

). Also there are a few shortcuts (like TAB and CTRL+TAB) to navigate betwee inline editors.
But if you have new value in clipboard you may just press CTRL+V (or click on Paste from context menu) on certain cell without activation of editor at all.