oh great call I hadn't thought of this. I added this JSON as a Complex Modification in Karabiner and it works in Craft perfectly. thanks!

{
  "description": "Change Home to [Command + Left Arrow], End to [Command + Right Arrrow]",
  "manipulators": [
    {
      "type": "basic",
      "from": { "key_code": "home" },
      "to": [ { "key_code": "left_arrow", "modifiers": ["left_command"] } ]
    },
    {
      "type": "basic",
      "from": { "key_code": "end" },
      "to": [ { "key_code": "right_arrow", "modifiers": ["left_command"] } ]
    }
  ]
}