Gboard has a toggle to disable/enable spellcheck completely, but using 3rd-party keyboards such as AnySoftKeyboard or SwiftKey shows this red-underline and suggestion-box that cannot be disabled.
The spellcheck is actually part of the Android system, not part of AnySoftKeyboard.
How can I disable spellcheck for the whole system? Or does the developer of the keyboard app always need to implement this feature?
In case it's relevant, I'm on Android 10, ColorOS 7.