The Ironsworn examples in System-Specific Roll Notation are incorrect. You use a d6 as the action dice, so rolls of 7 or 10 are never going to happen. Also, even if you somehow exceed 10 total with adds from assets and whatnot, the action roll is still capped at 10 (technically you could roll a miss with 6+4 = 10 vs 10 & 10 since ties go to the challenge dice).
Please open an issue or better a pull request on Github with a working example in the notation: https://github.com/zeruhur/lonelog