Control+backspace is a text-editing shortcut on Windows to delete words; it should not delete the entire math block in the default config

[CurtisFenner]

On Windows, Control+Backspace is a standard key combination that deletes the preceding word. At least on Windows, the behavior of deleting the entire math block is surprising.

(Mac uses different shortcuts; Option+Backspace deletes words and Command+Backspace deletes lines)

Alt+Backspace apparently means "undo" on Windows (TIL)