Karabiner Elements Double Shift Macro

{
    "title": "Both shift = backspace. Both shift 2x = delete word.",
    "rules": [
    {
        "description": "Both shift = backspace. Both shift 2x = delete word.",
        "manipulators": [
        {
            "type": "basic",
            "from": {
                "simultaneous": [
                    {
                        "key_code": "left_shift"
                    },
                    {
                        "key_code": "right_shift"
                    }
                ],
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "key_code": "delete_or_backspace",
                    "modifiers":[
                        "right_option"
                    ]
                }
            ],
            "conditions": [
                {
                    "type": "variable_if",
                    "name": "both_shift pressed",
                    "value": 1
                }
            ]
        },

        {
            "type": "basic",
            "from": {
                "simultaneous": [
                    {
                        "key_code": "left_shift"
                    },
                    {
                        "key_code": "right_shift"
                    }
                ],
                "modifiers": {
                    "optional": [
                        "any"
                    ]
                }
            },
            "to": [
                {
                    "set_variable": {
                        "name": "both_shift pressed",
                        "value": 1
                    }
                },
                {
                    "key_code": "delete_or_backspace"
                }
            ],
            "to_delayed_action": {
                "to_if_invoked": [
                    {
                        "set_variable": {
                            "name": "both_shift pressed",
                            "value": 0
                        }
                    }
                ],
                "to_if_canceled": [
                    {
                        "set_variable": {
                            "name": "both_shift pressed",
                            "value": 0
                        }
                    }
                ]
            }
        }
        ]
    }
    ]
}