Как убрать задержку переключения языка на Mac OS?
Source: https://apple.stackexchange.com/a/436729
1) System Preferences -> Keyboard -> Keyboard -> Press "globe" to: Do nothing
2) Установить https://karabiner-elements.pqrs.org/
3) На 12.1 при выдаче прав на  Input monitoring  будет отсутствовать karabiner_grabber. Нужно его добавить самостоятельно 
/Library/Application Support/org.pqrs/Karabiner-Elements/bin/karabiner_grabber

На всякий случай - тут ветка по решению типовых проблем https://github.com/pqrs-org/Karabiner-Elements/iss...

4) В karabiner.json добавить правило из ответа на stackexchange. Мой файл выглядит вот так:
karabiner.json{
    "global": {
        "check_for_updates_on_startup": true,
        "show_in_menu_bar": true,
        "show_profile_name_in_menu_bar": false
    },
    "profiles": [
        {
            "complex_modifications": {
                "parameters": {
                    "basic.simultaneous_threshold_milliseconds": 50,
                    "basic.to_delayed_action_delay_milliseconds": 500,
                    "basic.to_if_alone_timeout_milliseconds": 1000,
                    "basic.to_if_held_down_threshold_milliseconds": 500,
                    "mouse_motion_to_scroll.speed": 100
                },
                "rules": [
                    {
                        "description": "fn -> previous input source",
                        "manipulators": [
                            {
                                "from": {
                                    "key_code": "fn"
                                },
                                "to": [
                                    {
                                        "key_code": "fn"
                                    }
                                ],
                                "to_if_alone": [
                                    {
                                        "key_code": "spacebar",
                                        "modifiers": [
                                            "left_control"
                                        ]
                                    }
                                ],
                                "type": "basic"
                            }
                        ]
                    }
                ]
            },
            "devices": [],
            "fn_function_keys": [
                {
                    "from": {
                        "key_code": "f1"
                    },
                    "to": [
                        {
                            "consumer_key_code": "display_brightness_decrement"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f2"
                    },
                    "to": [
                        {
                            "consumer_key_code": "display_brightness_increment"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f3"
                    },
                    "to": [
                        {
                            "apple_vendor_keyboard_key_code": "mission_control"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f4"
                    },
                    "to": [
                        {
                            "apple_vendor_keyboard_key_code": "spotlight"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f5"
                    },
                    "to": [
                        {
                            "consumer_key_code": "dictation"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f6"
                    },
                    "to": [
                        {
                            "key_code": "f6"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f7"
                    },
                    "to": [
                        {
                            "consumer_key_code": "rewind"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f8"
                    },
                    "to": [
                        {
                            "consumer_key_code": "play_or_pause"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f9"
                    },
                    "to": [
                        {
                            "consumer_key_code": "fast_forward"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f10"
                    },
                    "to": [
                        {
                            "consumer_key_code": "mute"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f11"
                    },
                    "to": [
                        {
                            "consumer_key_code": "volume_decrement"
                        }
                    ]
                },
                {
                    "from": {
                        "key_code": "f12"
                    },
                    "to": [
                        {
                            "consumer_key_code": "volume_increment"
                        }
                    ]
                }
            ],
            "name": "Default profile",
            "parameters": {
                "delay_milliseconds_before_open_device": 1000
            },
            "selected": true,
            "simple_modifications": [],
            "virtual_hid_keyboard": {
                "country_code": 0,
                "indicate_sticky_modifier_keys_state": true,
                "mouse_key_xy_scale": 100
            }
        }
    ]
}

Вроде бы все. Семь бед - один reset, на случай глюков при установке
Рабочий вариант https://www.iphones.ru/iNotes/q/kak-na-lyubom-mac-...