karabiner - remap alt tab to different keys

Question

Is it possible to remap left_option + tab to alt-tab and left_option + shift + tab for reverse alt-tab?

Configuration below has problems with changing the direction of the selection, for example switching from alt-tab to alt-shift-tab first closes the alt-tab and opens another one.

Is it possible to catch all events while left_option is held down and check whether tab is pressed in combination with the shift?

   {
      "type": "basic",
      "from": {
        "key_code": "tab",
        "modifiers": {
          "mandatory": ["left_option"],
          "optional": ["caps_lock"]
        }
      },
      "to": [
        {
          "key_code": "tab",
          "modifiers": ["left_command"]
        }
      ]
  },
  {
      "type": "basic",
      "from": {
        "key_code": "tab",
        "modifiers": {
          "mandatory": ["left_option", "left_shift"],
          "optional": ["caps_lock"]
        }
      },
      "to": [
        {
          "key_code": "tab",
          "modifiers": ["left_command", "left_shift"]
        }
      ]
  },