i'm looking at this too in (IronJetpacks-1.18.2-5.1.2) while doing some custom recipe work in atm7 (0.4.18) for our late game stuff, and i've noticed that all of the components are tagged as above, but are correct when you look at their NBT data, it'll give Id: ironjetpacks:<material> with the material being whatever it is made of, eg diamond, or gold.

This might also be the cause of a bug i've noticed and thought was reported, where you could make any teir of jetpack with any other jetpack as a base model.
Example 1, a stone jetpack made from a silver one

Example 2, a Emerald Jetpack made from a wooden one

Originally posted by @Mitchell5200 in #52 (comment)