Questions

What level do connected Abilities act at?

Let's assume someone's got the Invulnerability Ability (page 108) at d10, with the "Recover your Injured or Exhausted Stress" Special Effect. They take some Injured Stress, raising Injured to d8. They spend a Plot Point, invoke the Special Effect, which eliminates the Stress entirely, since the level of the Ability (d10) is higher than the level of the Stress (d8). If the Stress had been equal to or greater than the Ability level, it would only have been stepped back one level. Got that?

OK, now let's assume someone's got the Kryptonian Heritage (page 100) at d10, but hasn't taken the Invulnerability Ability. They get some Injured Stress at d8, and add a die to Trouble to use the d8 Kryptonian trigger (Add a d6 to the Trouble pool to use a Special Effect from a connected Ability you don't have) to get use that same Invulnerability Special Effect.

So here's the question: Does the Recover ability act at the d10 level of the governing Heritage, and eliminate the Stress? Or does it act at d4 level, as if the character had just right now acquired the Invulnerability Ability, and therefore just step the Stress down to d6?

Exactly what does "a Special Effect from a connected Ability you don't have" mean?

So, Growth happens, and that second person, the one with the Kryptonian Heritage, gains the Invulnerability Ability, and takes that same Special Effect, letting them Recover Injured or Exhausted Stress for a Plot Point instead of having to add a d6 to Trouble. Now, can they still use that Heritage add-a-d6-to-Trouble thing to use other Invulnerability Special Effects?

Taking the phrase "a Special Effect from a connected Ability you don't have" literally, they can't, because Invulnerability is no longer an "Ability you don't have". But that seems ridiculous, that they lose access to Invulnerability Special Effects by taking Invulnerability.