The biggest mistake players make is trying to play these exercises at full volume too quickly. The Trumpet Herald forums emphasize that these exercises are "fantastic, especially if you build up slowly, adding one exercise at a time". Start at a mezzo-piano to mezzo-forte dynamic. The goal is fluidity and ease of movement between partials, not raw volume. If you feel tension, you are moving too fast or playing too loud.
Here’s a breakdown of the specific types of technical areas the book covers: irons flexibility trumpet pdf