Can't unset some hotkeys located in General section of Settings

[qwertier]

Hello, there're no too many shortcuts for the app. And I don't see anything like "Use Global Hotkeys" checkbox, that'd allow us to not use shortcuts at all. Or, as an alternative, there should be the possibility to select None or leave blank in the according field with shortcut inside. At least, this way is used in shortcut mapping for Chrome...