There's nothing in the original narrative that suggests the original poster was blindsided by an effort to derail his career, and ACMI operators do not have a reputation for attempting to do that.

If the original poster is still employed by the carrier and is simply going back for a second attempt with a possible extra sim session or additional training, then it's not much to get excited about. Bottom line, fly the airplane.

A training failure is a training failure, regardless of whether it occurred at a 135 operation or a 121 operation, and regardless of whether it happened at a dirty low-iife devil-may-care great-unwashed son-of-satan evil scumbag sorry-you-were-born-and-its-too-bad-you-never-got-the-level-of-training-I-had-in-the-military ACMI operator, or a thank-you-jesus vaunted closer-to-god realworld genuine blessed and holy and sacred legacy operator. It's a training failure.

The best revenge for careless living is to put distance and success between today and yesterday; if he's still employed, pass the checkride and move on.

Any training failure or black mark on one's historical record must be owned, not explained away, and it would be deeply inappropriate to infer that it's a lesser event because it occurred at an ACMI carrier, especially with the expectation of an "oh, it's just one of those scumbag operators" expectations. The classic It's-not-me-it's-them gambit. The original poster has already explained it, and will need to explain it for life, but should leave out any part of the explanation that implies it was anything but personal fault for which he accepts responsibility and from which he has learned. Simisms, check airmen antics, etc are excuses, not explanations and aren't a good look. I went low, I should have gone around, covers it.

For the original poster, there's a reason that the operator wants you to protect the FAF altitude on the MCP, isn't there?