The “Shift+Backspace” key combination is naturally used when typing some text in all-caps holding “Shift” (using “Caps Lock” sometimes is not very convenient for just a single word in caps). The Notepad and MS Word editors treat “Shift+Backspace” as regular “Backspace” which is very convenient — one may continue holding the “Shift” key while correcting the last letter typed. I believe that it would be better for EmEditor to handle it the same way. If the “Delete” behavior of “Shift+Backspace” is considered useful for some people, an option may be introduced in Settings.